A TREATISE ON 

DRY ROT m TIMBER 



T.A.BRITTON. 



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SKETCH OF DRY ROT FUNGUS 
On> hasenijUfiLiioorJowt iri' }wu/ie, cub GT'e4'/i^it}i,7W4a Lint dim 
Feb 1815. 



A TllEATISE 



ON THE 



3RIGIN, PROGRESS, PREVENTION, AND CURE 



OF 



DRY EOT IN TIMBER. 



WITH REMARKS ON 



THE MEANS OF PEESEEYING WOOD FROM DESTRUCTION BY 
SEA WORMS, BEETLES, ANTS, ETC, 



BY 



/ 



THOMAS ALLEN BRITTON, 

LATE SURVEYOR TO THE METROPOLITAN BOARD OF WORKS, AND SILVER 5IEDALLTST OF THE 
ROYAL INSTITUTE OF BRITISH ARCHITECTS IN 1854, 1856, AND 1870. 






LONDON: 

E. & F. N. SPON, 48, CHARING CROSS. 
NEW YORK : 446, BEOOME STREET. 

1875. 



tW/o 



THIS VOLUME 
IS 

g^Htattir to 
GEORGE VULLIAMY, Esq., 

VICE-PRESIDENT 

OF THE 

EOYAL INSTITUTE OF BRITISH ARCHITECTS; 

AND 

ARCHITECT 

OP 

THE METROPOLITAN BOARD OP WORKS ; 

AS A SLIGHT ACKNOWLEDGMENT 

OF HIS 

COUNSEL, SYMPATHY, AND FRIENDSHIP, 

DURING MANY YEARS. 



PREFACE. 



In preparing this treatise on Dry Eot, the author has 
endeavoured to place in as condensed a form as was con- 
sistent with the nature of the subject, the knowledge and 
information dispersed through a numerous collection of 
writers who have treated thereon ; he has also availed 
himself of the assistance of professional friends, builders, 
timber-merchants, foremen and carpenters ; and, by so 
doing, has been enabled to record several instances of the 
progress and cure of dry rot. He has consulted many 
valuable papers published during the last thirty years, in 
the various professional journals in England, America, 
France, and Germany, upon this important subject, and 
has also obtained much useful information from the works 
of Evelyn, Nicholson, Tredgold by Hurst, Pap worth, Bur- 
nell, Blenkarn, and other English writers upon timber; 
Silloway, of North America ; Porcher, of South America ; 
Du Hamel, De Morny, and De Lapparent, of France ; and 
several writers whose works will be referred to. 

It is many years since a separate and complete work on 
dry rot has been published, and those who are desirous of 
inquiring into the matter are frequently at a loss where 
to obtain any information. Existing works on the subject 
are out of print, and although they can be seen at a few 



VI PREFACE. 

professional institutes, they are beyond the reach of the 
general public. 

It has been the aim of the author in preparing this 
treatise to give a fair hearing to every patentee, and he 
has endeavoured to be as impartial as possible in record- 
ing instances of failure and success. If he has erred in 
any particular case, he will be happy, should this work 
reach a second edition, to make any necessary correction. 

The reader will probably find some things repeated in 
the course of the work ; this is in many cases unavoidable, 
and in some advisable ; for if by a little tautology im- 
portant truths can be impressed upon the mind of the 
reader, the author will feel that his labour in preparing 
this work has not been altogether in vain. 

Modern authorities have been relied upon in preference 
to ancient ones : the following sentence, written by the 
late Sydney Smith, is quoted as a reason for so doing : 

"Those who come first (our ancestors) are the yonng 
people, and have the least experience. We have added 
to their experience the experience of many centuries ; 
and, therefore, as far as experience goes, are wiser, and 
more capable of forming an opinion than they were." 



20, Limes Grove, Lewisham, 
May Uth, 1875. 



CONTENTS 



-•0*- 



CHAPTEK I. 
On the Nature and Properties of Timber Page 1 

CHAPTEE II. 

On the Gradual Eise and Development of Dry Rot 14 

CHAPTEE III. 
On Fellinor Timber 51 



'O 



CHAPTEE IV. 

On Seasoning Timber by Natural Methods, viz. Hot and Cold Air; 
Fresh and Salt Water ; Vapour ; Smoke ; Steam ; Boiling ; Charring 
and Scorching, &c 63 

CHAPTEE V. 

On Seasoning Timber by Patent Processes, &c 105 

CHAPTEE VI. 

On the Means of Preventing Dry Eot in Modem Houses 171 

CHAPTEE ^VII. 

On the Means of Preservation of Wooden Bridges, Jetties, Piles, 
Harbour Works, &c., from the Ravages of the Teredo navalis and 
other Sea-worms 203 



yill CONTENTS. 

CHAPTEE VIII. 

On the Destruction of Woodwork in Hot Climates by the Termite or 
White Ant, Woodcutter, Carpenter Bee, &c. ; and the Means of 
Preventing the Same Page 240 

CHAPTEE IX. 

On the Causes of Decay in Furniture, Wood Carvings, &c. ; and the 
Means of Preventing and Remedying the Effects of such Decay 262 

CHAPTEE X. 

Summary of Curative Processes 283 

CHAPTEE XI. 

General Remarks and Conclusion 288 

Index 295 



ILLUSTEATIONS, 



^ Dry Rot on Floor Joist Frontispiece 

To face page 
' TniBER Beams — Rotten at the Heart 34 

Baltic Modes of Cutting Deals 64 

Mr. Kyan's Timber Preserving Tank 126 

Messrs. Bethell and Co.'s Timber Preserving Apparatus.. .. 136 

Timber Piles from Balaclava Harbour 208 

Destruction of Timber Pile by Teredo 212 

V Shell and Cell of Teredo navalis 216 

Piles, Southend Pier; Limnoria, &c 220 

Carpenter Bees at Work 2G0 



A TREATISE 



ON 



DEY EOT IN TIMBEK 



CHAPTER L 

ON THE NATURE AND PROPERTIES OF TIMBER. 

In considering the subject of Timber trees, we commence 
with their Elementary Tissues, and first in order is the 
Formative Fluids which is the sole cause of production of 
every tissue found in trees. It is semi-fluid, and semi- 
transparent, and in this condition is found abundantly 
between the bark and the wood of all trees in early spring; 
and thus separates those parts so as to permit the bundles 
of young wood to pass down from the leaves, and thus 
enable the tree to grow. It is under these conditions 
that the woodman strips the bark from trees which are to 
be cut down, since then it does not adhere to the wood. 

The first step in the formation of any tissue from the 
formative fluid is the production of a solid structureless 
fabric called Elementary Membrane, and a modification of 
that fabric termed Elementary Fibre. 

The structures which are produced from the above- 

B 



Z PREVENTION AND CURE OF 

mentioned " raw material " are very varied in appearance, 
and are called Cellular Tissues, to signify that they are 
made up of hollow cells. The spaces between the cells are 
called Intercellular Spaces, which are of vital importance, 
as they contain air. Woody fibre constitutes the mass of 
the stems of our forest trees. Its peculiar characteristic 
is that of great tenacity, and power of resistance, and for 
this its structure is admirably adapted : it consists of 
bundles of very narrow fibres, with tapering extremities, 
and is so placed from end to end, that the pointed ends 
overlap each other. Each fibre is very short, and the parti- 
tions whicli result from the apposition of the fibres, end to 
end, do not interfere with the circulation through them. 
The tube is not composed of simple thin membraiies only ; 
but in addition has a deposit within it, which, without 
filling the tube, adds very greatly to the strength of the 
fibre : an arrangement whereby the greatest strength and 
power of resistance and elasticity shall be obtained ; and, 
at the same time, the functions of circulation uninter- 
ruptedly maintained. The strength is mainly due to the 
shortness of each fibre, the connection by opposite ends of 
many fibres, almost in one direct line, from the root up- 
wards ; and lastly, to the deposit on the inner side of the 
membrane. The uses of woody fibre are very varied and 
most important ; it is the chief organ of circulation in all 
wooded plants, and, for this purpose, pervades the plant 
from the root to the branches. The current in this tissue 
is directed upwards from the shoot, through the stem to 
the leaves, and downwards from the leaves through the 
bark to the root. Thus, its current has a twofold ten- 



DRY ROT IN TIMBER. 3 

dency ; the ascending and chief one being for the purpose 
of taking the raw, or what is called the common sap, from 
the ground to be digested in the leaves, and the descend- 
ing being devoted to the removal from the leaves of the 
digested, or what is termed the jproioer sap, to be applied 
to the purposes of the tree, and also of the refuse matter 
to be carried to the roots, and thence thrown out into the 
soil as a noxious material. The proper sap differs con- 
siderably in different trees ; it is always less liquid, and 
contains a much greater proportion of vegetable matter 
than the common sap. It is very probable that trees of 
the same kind produce proper sap of different qualities in 
different climates. 

Woody Fibre may be considered the storehouse of the 
perfected secretions. It is well known that as trees ad- 
vance in life, the wood assumes a darker colour, and more 
particularly that lying near to the centre of the stem. 
This is due to the deposit of the perfected juices in the 
woody fibre at that point ; and where age has matured the 
tree, it is probable that the woody fibre so employed is no 
longer fitted for the circulation of the sap ; and, also, that 
the perfected sap, when once deposited, does not again join 
in the general circulation. The dark colour of the heart 
of oak, as contrasted with oak of very recent growth, is an 
illustration of this fact, as is also the deep colour which is 
met with in ebony and rosewood. Technically, the inner 
wood is called the heart-wood, and the outer or younger 
wood the sap-wood. Of these, the former contains little 
fluid, and no vegetable life, and, being the least liable to 
decay, is therefore the most perfect wood; the latter is 

B 2 



4 PREVENTION AND CURE OF 

soft and perishable in its nature, abounding in ferment- 
able elements ; thus affording the very food for worms, 
whose destructive inroads hasten its natural tendency to 
decay. 

The proportion of sap-wood in different trees varies very 
much. Spanish chestnut has a very small proportion of 
sap-wood, oak has more, and fir a still larger proportion 
than oak ; but the proportions vary according to the situa- 
tion and soil, and according to the age at which they have 
been felled : for instance, the teak tree in Malabar, India, 
differs from teak in Anamalai, South India. This subject 
has been very fully treated by Mr. Patrick Williams, in 
his valuable work on Naval Timber. 

Wooded Stems are divided into two great and well- 
defined classes, according to their internal conformation, 
viz. such as grow from without (exogenous), and such as 
enlarge from within (endogenous). The former are more 
common in cold, and the latter in hot climates. 

Exogenous Stems. — On examining a section of a stem 
of an oak, or any other of our forest trees, we observe the 
following parts : first, the pith, or its remains in the centre ; 
second, the bark on the outside; third, a mass of wood 
between the two, broken up into portions by the concentric 
deposition of the layers, and by a series of lines which pass 
from the centre to the circumference. Thus, there are 
always pith, bark, wood, and medullary rays. Each stem 
has two systems, the cellular or horizontal, and the 
vascular or longitudinal, and the parts just mentioned 
must belong to one or other of those systems. Thus, 
the pith, medullary rays, and bark belong to the hori- 



DRY ROT IN TIMBER. 5 

zontal system ; and the wood constitutes the longitudinal 
system. 

The Pith occupies the centre of the stem, and remains 
throughout the period of growth of some trees, as of the 
elder; or is abstracted after a few years, as in the oak, 
and almost all large trees. In the latter class of trees, 
there are some remains of the pith for many years after 
the process of absorption has commenced, but at length no 
vestige can be detected, and its position is known only 
by the central spot around which the wood is placed in 
circles. In the old age of the tree the pith frequently 
assumes a colour which it has obtained from the juices 
which have been deposited. The connections of the pith 
are extremely important. Firstly, it is in direct connection 
with every branch, and is the structure which first con- 
veys fluids to, and receives fluids from every new leaf. It 
thence becomes the main organ of nutriment, and, at the 
same time, the chief depository of the secretions. Secondly, 
it is in equally direct and unbroken connection with the 
bark, through the medium of the medullary rays ; and so 
becomes the centre of all the movements of sap which 
proceed in the horizontal system. 

The mode in which the ultimate disappearance of the 
pith occurs has been a matter of speculation. That the 
circulation in the heart-wood ceases after a certain 
number of years, and that the connection between it and 
the bark becomes broken, is proved by the fact that 
numbers of trees may be found in tolerably vigorous 
growth within the bark, whereas at the heart they are 
decayed and rotten. It appears clear that it is not con- 



6 PREVENTION AND CURE OF 

verted into wood, and there are facts against the opinion 
that it is gradually compressed by the wood ; but since it 
is known that in the growth of the tree much compression 
of the previously formed wood must occur, and since this 
compression is a likely theory by w^hich to account for the 
disappearance of the less resisting pith, it is now generally 
considered to be one of the causes of this occurrence. As 
a general rule, the pith, so long as it exists, is not mingled 
with other than cellular structures ; but, in certain 
instances, wooden fibre has been found with it, and, in 
others, spiral vessels have been detected. 

Medullary Sheath. — Immediately surrounding the 
pith of all exogenous plants, there is a layer of longi- 
tudinal tissue, which has received the name of medullary 
sheath. This sheath has no special walls, but is bounded 
by the pith on the inner, and the wood on the outer side. 
It is in this situation that ducts of various kinds and 
spiral vessels may be found, and in all cases it conveys the 
longitudinal structure from the root, direct to each leaf. 
The integrity of this structure is therefore highly neces- 
sary to the life of the tree. 

Medullary Eays. — These structures come next in 
order, and, as has been previously intimated, belong to 
the horizontal cellular system of the stem ; they constitute 
the channel of communication between the bark and the 
pith, and are composed of a series of walls of single cells 
resting upon the root, and proceeding to the top of the 
tree, and radiating from the centre. They lie between 
the wedge-like blocks of wood, and as they have a lighter 
colour than the wood, they are evident on an oblique sec- 



DRY ROT IN TIMBER. 7 

tion of any stem, and are called the silver grain. Their 
colour and number suffice to enable anyone to distinguish 
various kinds of wood, and greatly increase their beauty. 
They cannot, of course, exist before the wood is formed, 
and are therefore not met with in very young trees. They 
commence to exist with the first deposited layers of wood, 
and continue to grow outwardly, or nearest to the bark, so 
long as the wood continues to be deposited. In those 
woods which possess in abundance the silver grain, 
another source of ornament exists, viz. a peculiar damask 
or dappled effect, somewhat similar to that artificially 
produced on damask linens, moreens, silks, and other 
fabrics, the patterns on which result from certain masses 
of the threads on the face of the cloth running length- 
ways, and other groups crossways. This effect is observ- 
able in a remarkable degree in the more central planks of 
oak, especially in Dutch wainscot. 

The Bark. — As the medullary rays terminate in the 
bark, on their outer side, the consideration of that part 
next follows. It forms the sheath of the tree, and its 
more immediate use is that of giving protection to the 
wood. If bark did not exist, there would be no forma- 
tive fluid, and without formative fluid there could not be 
any deposit of woody fibre. 

Wood. — We find wood occupying nearly the whole 
body of the trunk of the tree, and arranged, as a rule, in 
a very regular manner. On taking up any piece of wood, 
but more particularly the entire section of a stem, we 
first notice a series of circles, which increase in diameter 
and separate by wider intervals as we approach the bark. 



8 PREVENTION AND CURE OF 

In this manner the trunk is composed of numerous zones 
enclosed within each other. Again, in almost all trees, 
the medullary rays before mentioned may be observed 
passing in straight lines from the centre to the circum- 
ference; and, as the circle of the stem at the bark is much 
larger than any circle near to the centre, it follows that 
the medullary rays will be wider apart at the bark than 
at the pith. On this view of the subject it may be stated 
that the stem is composed of a series of wedge-shaped 
blocks, which have their edges meeting at the centre. 
The combination of these two views gives the correct idea 
of the arrangement of the wood, viz. a series of wedges, 
each divided into segments of unequal width by circular 
lines passing across them. From this description it must 
not be imagined that these various portions are detached 
from each other ; for although the medullary rays and the 
circular mode of deposition both tend to a less difficult 
cleavage of the wood, they yet bind the parts very closely 
to each other. 

The explanation of the occurrence of distinct zones of 
wood is, that each zone is the produce of one year, and 
that in our climate, more so than in tropical climates, the 
period of growth of wood ceases for many months between 
the seasons, and this induces a distinction in appearance 
between the last wood of a former, and the first wood of a 
succeeding year. This distinction is maintained through- 
out each year, and throughout a long series of years. 

The enclosure of zone within zone, is owing to the 
mode in which the wood is produced, and the position in 
which it is deposited. Wood is formed by the leaves 



DRY ROT IN TIMBER. 9 

during the growing season, and passes down towards the 
root between the bark and the wood of the previous year ; 
and, as the leaves more or less surround the whole stem, 
the new layer at length completes a zone, and perfectly 
encloses the wood of all former years. This is the ex- 
planation of the term exogenous, which is derived from 
two words signifying to grow outwardly, for the stem 
increases in thickness by successive layers on the outer 
side of the previously formed wood. 

The thickness of the zone for the year is rarely equal 
around the whole circumference of the stem, and this is 
due to the lesser abundance of leaves on the branches of 
one side than on the other, or to the prevalence of winds, 
or some other physical cause, acting in that direction in 
opposition to the growing process. It should be observed 
that there is not in timber any appearance of a gradual 
change from alburnum to perfect wood. On the contrary, 
in all cases the division is most decided ; one concentric 
layer being perfect wood, and the next in succession sap- 
wood. 

The age of trees has been inferred, when a section of 
the whole stem could be examined, by counting the 
number of rings of wood which have been deposited 
around the pith. In tropical countries, however, this 
method cannot be always relied upon. 

Woods are variable in quality according to the nature 
of the climate, and of the soil, as also in a considerable 
degree to the aspect in which they are situated. Trees 
grown slowly in open, dry, and exposed situations are 
more fine and close in their annual rings, and more sub- 



10 PREVENTION AND CURE OF 

stantial and durable, than those which are grown in close 
and shady forests, or rapidly reared in moist or sappy 
places, the latter being soft and broad in their rings, and 
very subject to decay ; and their pith is not always quite 
in the centre, for the layers are variable also. 

The waggon maker takes care to combine toughness 
and durability by selecting his wood from trees of second 
growth, or from trees of first growth that from infancy 
have stood alone, or far apart. If the soft wood trees have 
stood alone, and are very large (as is often the case with 
some of the pines), and most of the branches are near the 
top, the wood near the base of the trunk is sometimes 
found to be shaky. This defect is produced by the action 
of heavy winds on the top of the tree, which wrenches or 
twists the butt, and thus cleaves apart the fibres of the 
wood. If the main-top (eouronnement, of French writers) 
of a tree dies while the tree is yet standing, it indicates 
that water has found its way into the trunk, and that the 
tree is in a state of decay. 

The fir which grows on very dry marl, forms very 
narrow yearly rings ; if on rich or damp marl, they are 
wide ; and when on wet soil, they are again smaller. The 
common fir on moor soil, has even smaller yearly rings 
than if on dry sand or marl. From this it is evident 
that too wet or too dry a soil is not suitable for this tree. 

The alder and the willow grow best on wet soil, and 
thrive but poorly when standing dry. 

The weight of wood is of great importance, because its 
hardness, resistance, and its heating power, as well as 
other valuable properties, are all more or less depending 



DRY EOT IN TIMBER. 11 

upon it. In the first place, we must consider that even 
wood which has been forested very light will become 
heavy, when put for some time into water, but in such 
timbers the sap is already given to dissolution. If the 
fibre were the only substance in the wood, then the specific 
weight would depend upon the number of pores contained 
in its body ; the pores are, however, filled with a substance 
such as resin, die, &c. Some years since, when the Indian 
railways were being formed, the native woodcutters were 
so well aware of the above-mentioned fact, that they used 
to cut down the soft and inferior woods in the forests ; soak 
them in water for a certain time ; and then endeavour to 
pass them to the railway contractors as sound, heavy, and 
good railway sleepers, and the latter, not being acquainted 
with the Indian woods, were, at first, often deceived. 

The hardest, and heaviest woods come from the hotter 
climates ; the only exception is the pine, which thrives con- 
siderably better, and furnishes heavier timber, when it has 
grown in colder regions, or upon high mountains. 

Trees grown on northern slopes furnish lighter timber 
than if grown on southern or western. The soil has great 
influence upon the width of the yearly rings, and from 
this we are able to come to a conclusion in regard to the 
specific weight. In the fir and larch trees the wood is 
heaviest when their rings are smallest. 

The difference in the strength of timber between the 
south and the north side is attributable to the grain being 
closer on the north side, as the sap does not rise in the 
same proportion as upon the south. In forest-grown 
wood the difference is almost imperceptible, as the sun 



12 PREVENTION AND CURE OF 

cannot act upon the trunk of the tree; in open-grown 
timber, the difference is really perceptible. It is well 
known that all woods do not lose strength by' being open 
grown, or, in other words, that the south side is not always 
weaker than the north ; that theory only applies to the 
coniferae species. In ash it is the opposite, as the south 
side is the strongest. In soft-wooded trees, as the acer 
species, the difference is not perceptible, as the annual 
rings, and the intervening cellular tissues, are so close 
akin as to render the wood so compact in its grain that 
there is no difference in its strength. The coniferae 
species, or the pines, are the only classes of woods that 
are stronger on the north side than on the south : it is 
well known that the difference originates in the wood 
being more open in the grain on the south side than on 
the north. 

An influence upon the specific weight is exercised by 
the resin, and the die, which are contained in the interior 
of the wood. On level dry ground, or deep sandy soil, 
we find the fir beautifully red inside ; but when we look 
at it on lias soil, it shows broad yearly rings, and hardly 
any colour at all. The larch tree, again, in such soil, 
develops itself well with a rich colour. The cause for 
these appearances must therefore rest with the chemical 
condition of the soil, and its effect upon the individuality 
of the fir : it is probably the nature of the soil that causes 
the difference of character between Honduras and Spanish 
mahogany ; Honduras being full of black specks, and 
Spanish of minute white particles, as if it had been 
rubbed over with chalk. Oaks generally furnish good 



DRY ROT IN TIMBER. 13 

timber when grown slowly in dry ground, whilst those 
from wet soil appear comparatively spongy; similar results 
are obtained with other trees. 

Many persons constantly employed on wood are of 
opinion that it becomes harder if it is worked or barked 
whilst green. 

It is not safe to condemn timber, merely because long 
cracks are visible on the surface. Such openings are 
frequently only superficial, and do not penetrate deeply 
into the wood : in such cases it is very little weakened 
thereby. It is difficult to obtain timber of large scantling 
without some defects of this kind, but care should be 
taken to ascertain if they are of a serious nature. 

Trees arrive at an age when their wood becomes ripe, 
and then they are fit for felling ; but as upon the proper 
method and time for doing this, the prevention of dry rot 
frequently hinges, a separate chapter is devoted to this 
part of the subject. 



14 PREVENTION AND CURE OF 



CHAPTER 11. 

ON THE GKADUAL RISE AND DEVELOPMENT OF 

DRY ROT. 

The opinion generally received has drawn a line of dis- 
crimination between the decay accompanied by a vegetable 
spreading on the surface of the timber, and that which is 
effected by an animal existing within it, which decay is 
frequently denominated the worm in timber ; but as each 
is equally entitled to the dreaded appellation, they might 
more justly be distinguished as the animal and vegetable 
rot. 

The dry rot in timber derives its name from the effect 
produced, and not from the cause : it is so called in oppo- 
sition to the wet rot, which is properly denominated, as 
this exists only in damp situations, and is applied to the 
decomposition which takes place in timber containing sap, 
and exposed to moisture: but although the dry rot is 
usually generated in moisture, in some cases it will flourish 
independent of extraneous humidity. Dry rot differs 
from wet rot in this respect, that the former takes place 
only when the wood is dead, whereas the latter may begin 
when the tree is standing. 

Wet rots are composed of porous fibre running from the 
rot into the trunk of the tree. This rot is of a brown 
colour, and has an offensive smell. The evil is often 



DRY ROT IN TIMBER. 15 

found with white spots, the latter of watery substance : 
when it has yellow flames, it is very dangerous. 

A large quantity of the vegetable kingdom consists 
of plants differing totally from the flowering plants in 
general structure, having no flowers and producing no 
seed properly so called, but propagating by means of 
minute cellular bodies, called sjpores. These highly or- 
ganized vegetables are known to botanists as Cryjptogamia. 
Fungi are plants in which the fructifying organs are so 
minute, that without the aid of a powerful microscope 
they cannot be detected. To the naked eye, the fine dust 
ejected from the plant is the only token of reproduction ; 
this dust, however, is not truly seed, for the word seed 
supposes the existence of an embryo, and there is no such 
thing in the reproductive bodies of fungi. The correct 
terms are scores, when the seeds are not in a case ; sjooridia 
when enclosed in cases. The spores or sporidia are placed 
in or upon the receptacle, which is of very various forms 
and kinds, but how different soever these may be, it is the 
essential part of the fungus, and in many cases constitutes 
the entire plant. That portion of the receptacle in which 
the reproductive bodies are imbedded is called the 
hymenium : it is either external, as in the Agaric, where 
it forms gills ; or included, as in the puff-balls. The 
pileus of fungi is the entire head of the plant, not a 
mere head covering. 

Some naturalists have insisted upon the spontaneous 
production of fungi, while others maintain that they are 
produced by seed, which is taken up and supported in the 
air until a soil proper for its nourishment is presented, on 



16 PREVENTION AND CURE OF 

which being deposited it springs up of various appearances 
according to the principle of the seed, and the nature of 
the recipient. 

It is extremely difficult to give a logical definition of 
what constitutes a fungus. It is not always easy with a 
cursory observation under the microscope, to determine 
whether some appearances are produced by fungi, insects, 
or organic disease ; experience is the safest guide, and 
imtil we acquire that we shall occasionally fail. 

In the ' Index Fungorum Britannicorum/ 2479 species 
of British fungi are enumerated : any detailed account of 
the arrangement of this extensive family of plants, or 
of the character of even its principal sections would be 
impossible within the limits of this volume ; all that can 
be attempted will be a general description of the fungi 
causing dry rot. 

If dry rot shows itself in a damp closet or pantry, the 
inside of the china or delf lying there will be coated 
with a mould, or a fine powder like brickdust. This 
excessively fine powder is no other than unaccountable 
myriads of the reproductive spores or seeds of the fungus ; 
they are red in colour, and are produced on the surface 
of the fungus in millions. Certain privileged cells on the 
face of the fungus are furnished each with four minute 
points at their apex, each four bearing a single brick-red, 
egg-shaped spore; so that the fruit is spread over the 
surface of the fungus in groups of fours. To see the 
form of these spores the highest powers of the microscope 
are required, and then they can only be viewed as trans- 
parent objects. If these excessively minute bodies be 



DRY EOT IN TIMBER. 17 

allowed to fall on wet flannel, damp blotting-paper, or 
wet w^ood, they immediately germinate and proceed to 
reproduce the parent fungus. The red skin of the spores 
cracks at both ends, and fine mycelial filaments are sent 
out: this is the "mould," spawn, or mycelium from 
which the new fungus (under favourable conditions of con- 
tinued moisture) appears. 

It matters little where we go: everywhere we are 
surrounded with life. The air is crowded wdth birds and 
insects ; the waters are peopled with innumerable forms, 
and even the rocks are blackened with countless mussels 
and barnacles. If we pluck a flower, in its bosom we see 
many a charming insect. If we pick up a fallen leaf, 
there is probably the trace of an insect larvae hidden in 
its tissue. The drop of dew upon this leaf will probably 
contain its animals, visible under the microscope. The 
very mould which covers our cheese, our bread, our jam, 
or our ink, and disfigures our damp walls, is nothing but 
a collection of plants. 

The starting point of life is a single cell — that is to say 
a microscopic sac filled with liquid and granules, and 
having within it a nucleus, or smaller sac. From this 
starting point of a single cell, this is the course taken : 
the cell divides itself into two, the two become four, the 
four eight, and so on, till a mass of cells is formed. 

The researches of Pasteur show that atmospheric dust 
is filled with minute germs of various species of animals 
and plants, ready to develop as soon as they fall into a 
congenial locality. He concludes that all fermentation is 
caused by the germination of such infinitesimal spores. 

c 



18 ' PREVENTION AND CURE OF 

That they elude observation does not seem strange, when 
we consider that some infusoria are. only ^r^^wu of an 
inch in lecgth. 

It is ascertained that fungi produce seed which contains 
the properties of germination ; and that vegetable cor- 
ruption is suited to effect it. When we contemplate the 
fineness and volatility of the germs, the hypothesis will 
not appear unreasonable that they are conveyed by the 
rains into the earth, and are absorbed by vegetables ; 
that with the sap they are disseminated throughout the 
whole body, and begin to germinate as soon as the 
vegetable has proceeded to corruption. Whatever, there- 
fore, may be the appearance or situation of the fungus 
producing the dry rot, or from whatever substance it 
originates, that substance must be in a corrupt state. 

Fungi result from, or are attendant on, vegetable cor- 
ruption, assisted by an adequate proportion of heat and 
moisture. The sap, or principle of vegetation, brought 
into activity, is, according to the ^ Quarterly Eeview,' 
No. 15, the cause of dry rot, in as far as it is favourable 
to the growth of fungi, as it would seem to be when in a 
state of fermentation. 

Vegetable corruption invariably presupposes fermenta- 
tion. 

Fermentation is a state of vegetable matter, the com- 
ponent parts of which have acquired sufficient force to 
produce an intestinal motion, by which the earthy saline, 
the oily and aqueous particles therein contained, exert 
their several peculiar attractive and repulsive powers, 
forming new combinations, wliich at first change, and at 



DRY ROT IN TIMBER. 19 

length altogether destroy the texture of the substance ) 
they formerly composed. 

There are two things essential towards creating and sup- 
porting the intestinal motion, namely, heat and humidity ; 
for without heat, the air, which is supposed, to be the 
cohesive principle of all bodies, cannot be so rarefied as to 
resume its elasticity ; and without humidity there can be 
no intestinal motion. 

According to Baron Liebig, the decay of wood takes 
place in the three following modes : — First, oxygen in the 
atmosphere combines with the hydrogen in the fibre, and 
the oxygen unites with the portion of carbon of the fibre, 
and evaporates as carbonic acid : this process is called 
decomposition. Second, we have to notice the actual decay 
of wood which takes place when it is brought in contact 
with rotting substances; and the third process is called 
putrefaction. This is stated by Liebig to arise from the 
inner decomposition of the wood in itself: it loses its 
carbon, forms carbonic acid gas, and the fibre, under the 
influence of the latter, is changed into white dust. 

The fungus occasioning the dry rot is of various appear- 
ances, which differ according to the situation in which it 
exists. In the earth, it is fibrous and perfectly white, 
ramifying in the form of roots; passing through sub- 
stances from the external surface, it somewhat differs 
from that form ; here it separates into innumerable small 
branches. 

Mr. McWilliam observes, " If the fungi proceed from 
the slime in the fissures of the earth, they are gene- 
rally very ramous, having round fibres shooting in every 

c 2 



20 PBEYENTION AND CURE OF 

direction. If they arise from the roots of trees, their first 
appearance is something like hoar frost ; but they soon 
assume the mushroom shape." 

Hence it appears that we frequently build on spots of 
ground which contain the fundamental principle of the 
disease, and thus we are sometimes foiled in our endea- 
vours to destroy the fungus by the admission of air. In 
this case the disease may be encouraged by the applica- 
tion of air as a remedy. When workmen are employed 
in buildings which contain dry rot, and when they are 
working on ground which contains the symptoms of this 
disease, their health is often affected. A London builder 
informs us, that a few years since, while building some 
houses at Hampstead his men were never well : he after- 
wards ascertained that the ground was affected with rot, 
and that within one year after the house was erected, all 
the basement floor was in a state of premature decay. 
Sir Kobert Smirke, architect, remarked in 1835, that he 
had noticed " there are certain situations in which dry. rot 
prevails remarkably." 

The fungus protruded in a very damp situation is fibrous, 
of moderate thickness, feels fleshy. From the spot whence 
it arises it extends equally around, wholly covering the 
area of a circle. This form would possibly continue in 
whatever situation it might vegetate, if the air had no 
motion, and every part of the substance on which it grew 
were equally supplied with a matter proper to encourage 
the expansion. The surface of this fungus is pursed, and 
of various colours, the centre is of a dusky brown, mixed 



DRY ROT IN TIMBER. 21 

with green, graduated into a red, wbicli degenerates into 
yellow, and terminates in white. 

One of the most formidable of the tribe of fungi is the 
Merulius lachrymans (often called the Dry Kot) of wliich 
the following description is given by Dr. Greville : " Whole 
plant generally resupinate, soft, tender, at first very light, 
cottony, and white. When the veins appear, they are of a 
fine yellow, orange, or reddish brown, forming irregular 
folds, most frequently so arranged as to have the appear- 
ance of pores, but never anything like tubes, and distilling, 
when perfect, drops of water.'' Hence the term lachrymans, 
from lacrymo^ Lat., I weep : the Merulius lachrymans is 
often dripping with moisture, as if weeping in regret for 
the havoc it has made. In the genus Merulius^ the texture 
is soft and waxy, and the hymenium is disposed in porous 
or wavy toothed folds. Berkeley, in his ' Fungology,' 
gives the following description, which is similar to Dr. 
Greville's : " Large, fleshy but spongy, moist, ferruginous 
yellow, arachnoid and velvety beneath ; margin tomentose, 
white ; folds ample, porous, and gyroso-dentate." The 
Merulius is found in cellars and hollow trees, sometimes 
several feet in width, and is the main cause of dry rot. 

Another formidable fungi, which attacks oak in ships, 
is the Polyporus hyhridus (the dry rot of our oak-built 
vessels). It is thus described by Berkeley : '' White, 
mycelium thick, forming a dense membrane, or creeping 
branched strings, hymenium breaking up into areae, pores 
long, slender, minute." 

From the slow progress dry rot makes in damp situa- 



22 PREVENTION AND CUKE OF 

tions, it appears tbat excessive damps are inimical to the 
fungus, for its growth is more rapid in proportion as the 
situation is less damp, until arrived at that certain degree 
of moisture which is suited both to its production and 
veojetation. When further extended to drv situations, its 
effects are considerably more destructive to the timber on 
which it subsists: here it is very fibrous, and in part 
covered with a light brown membrane, perfectly soft and 
smooth. It is often of much greater magnitude, projecting 
from the timber in a white spongeous excrescence, on the 
surfaces of which a profuse humidity is frequently observed : 
at other times, it consists only of a fibrous and thin-coated 
web irregularly on the surface of the wood. Excrescences 
of a fungiform appearance are often protruded amidst those 
already described, and are evidences of a very corrupt 
matter peculiar to the spots whence they spring. Accord- 
ing to the situation and matter in which they are produced, 
they are dry and tough, or wet, soft, and fleshy, sometimes 
arising in several fungiforms, each above the other, without 
any distinction of stem ; and when the matter is differently 
corrupted, it not unfrequently generates the small acrid 
mushroom. 

Mr. McWilliam observes, " The fungi arising from oak 
timbers are generally in clusters of from three to ten or 
twelve ; while those from fir timber are mostly in single 
plants : and these will continue to succeed each other 
until the wood is quite exhausted." 

Damp is not only a cause of decay, but is essential to 
it ; while, on the other hand, absolute wet, especially at a 
low temperature, prevents it. In ships this has been par- 



DRY ROT IN TIMBER. 23 

ticularly remarked, for that part of the liold of a sliip 
which is constantly washed by the bilge-water is never 
affected with dry rot. Neither is that side of the plank- 
ing of a ship's bottom which is next the water foimd in a 
state of decay, even when the inside is quite rotten, unless 
the rot has penetrated quite through the inside. 

It matters little whether wet is applied to timber before 
or after the erection of a building. Timber cannot resist 
the effect of what must arise in either case ; viz. heat and 
moisture, producing putrid fermentation ; for instance, in 
basement stories with damp under them, dry timber is but 
little better than wet, for if it is dry it will soon be wet ; 
decay will only be delayed so long as the timbers are 
absorbing sufficient moisture, therefore every situation 
that admits moisture is the destruction of timber. 

In a constancy and equality of temperature timber will 
endure for ages. Sir Christopher Wren, in his letter to 
the Bishop of Eochester, inserted in Wadman's ' History 
of Westminster Abbey,' notices " That Venice and 
Amsterdam being both founded on wooden piles immersed 
in w^ater, would fall if the constancy of the situation of 
those piles in the same element and temperature did not 
prevent the timber from rotting." Nothing is more 
destructive to woodwork than jpartial leaks, for if it be 
kept always wet or always dry, its duration is of long con- 
tinuance. It is recorded that a pile was drawn up sound 
from a bridge on the Danube, that parted the Austrian 
and Turkish dominions, which had been under water 1500 
years. 

The writer of an article on the decav of wood, in the 



24 PREVENTION AND CURE OF 

' Encyclopaedia Britannica/ 1855, observes, " If a post of 
wood be driven into the ground, the decay will commence 
at the surface of the ground ; if driven into the earth 
through water, the decay will commence at the surface of 
the water ; if used as a beam let into a damp wall, rot 
will commence just where the wood enters the wall." 

Humboldt observes in his ' Cosmos/ with reference to 
damp and damp rooms, that anyone can ascertain whether 
a room is damp or not, by placing a weighed quantity of 
fresh lime in an open vessel in the room, and leaving it 
there for twenty-four hours, carefully closing the windows 
and doors. At the end of the twenty-four hours the lime 
should be reweighed, and if the increase exceeds one per 
cent, of the original weight, it is not safe to live in the room. 

Decay of timber will arise from the effects of continued 
dryness or continued wetness, under certain conditions ; or 
it may also arise from the effect of alternate dryness and 
moisture, or continued moisture with heat. 

At one time dry rot appears to have made great havoc 
amongst the wooden ships of the British Navy. In the 
Memoirs of Pepys, who was Secretary to the Admiralty 
during the reigns of Charles II. and James II., reference 
is made to a Commission which was appointed to inquire 
into the state of the navy, and from which it appears that 
thirty ships, called new ships, " for want of proper care 
and attention, had toadstools growing in their holds as big 
as one's fists, and were in so complete a state of decay, 
that some of the planks had dropped from their sides." 

In the 'European Magazine' for December, 1811, it is 
stated that, " about 1798, there was, at Woolwich, a ship 



DRY ROT IN TIMBER. 26 

in SO bad a state that the deck sunk with a man's weicrht, 
and the orange and brown coloured fungi were hanging, 
in the shape of inverted cones, from deck to deck." 

Mr. William Chapman, in his ' Preservation of Timber 
from Premature Decay/ &c., gives several instances of the 
rapid decay of the ships of the Eoyal Navy, about the 
commencement of the present century. He mentions 
three ships of 74 guns each, decayed in five years ; three 
of 74 guns each, decayed in seven years ; and one of 100 
guns, decayed in six years. Mr. Pering, also, in his ^ Brief 
Enquiry into the Causes of Premature Decay,' &c., says 
that ships of war are useless in five or six years ; and he 
estimates the average duration to be eight years, and that 
the cost of the hull alone of a three-decker was nearly 
100,O00Z. Mr. Pering was formerly at the dockyard, 
Plymouth, and therefore a good authority, if he availed 
himself of the opportunities of studying the subject. He 
has stated that he has seen fungi growing so strong 
betwixt the timbers in a man-of-war, as to force a plank 
from the ship's side half an inch. 

No doubt a great deal of this decay was attributable to 
the use of unseasoned timber, and defective ventilation ; 
but there is too much reason to believe that it was prin- 
cipally owing to the introduction of an inferior species of 
oak (Quercus sessiliflora) into the naval dockyards, where, 
we imagine, the distinction was not even suspected. The 
true old English oak {Quercus robiir) affords a close- 
grained, firm, solid timber, rarely subject to rot ; the other 
is more loose and sappy, very liable to rot, and not half 
so durable. 



26 PREVENTION AND CURE OF 

One cause of the decay of wood in ships is the use of 
wooden treenails. A treenail is a piece of cleft wood 
(made round), from 1 foot to 3 feet 6 inches in length 
and IJ inch in diameter. As the treenails are also 
made to drive easy, they never fill the holes they are 
driven into ; consequently, if ever it admits water at the 
outer end, which, from shrinking, it is liable to do, that 
water immediately gets into the middle of the plank, and 
thereby forms a natural vehicle for the conveyance of 
water. The treenail is also the second thing which 
decays in a ship, the first, generally, being the oakum. 
Should any part of the plank or timbers of a ship be in an 
incipient state of decay, and a treenail come in contact 
with it, the decay immediately increases, while every 
treenail shares the same fate, and the natural consequence 
is, the ship is soon left without a fastening. Treenails in 
a warm country are sure to shrink and admit water. 

Mr. Finchara, formerly Principal Builder in Her 
Majesty's dockyard, Chatham, considers that the destruc- 
tion of timber by the decay commonly known as dry rot, 
cannot occur unless air, (?) moisture, and heat are all 
present, and that the entire exclusion of any of the three 
stays the mischief. By way of experiment, he bored a 
hole in one of the timbers of an old ship built of oak, 
whose wood was at the time perfectly sound ; the admis- 
sion of air, the third element, to the central part of the 
wood (the two others being to a certain degree present) 
caused the hole to be filled up in the course of twenty-four 
hours with mouldiness, which very speedily became so 
compact as to admit of being withdrawn like a stick. 



DRY ROT IN TIMBER. 27 

The confinement of timber under most circumstances is 
attended witii the worst consequences, yet a partial venti- 
lation tends to fan the flame of decay. 

The admission of air has long been considered the only 
means of destroying the fungus, but as it has frequently 
proved ineffectual, it must not be always taken as a certain 
remedy. If dry air be properly admitted, in a quantity 
adequate to absorb the moisture, it will necessarily ex- 
haust and destroy the fungus ; but care should be taken 
lest the air should be conveyed into other parts of the 
building, for, after disengaging itself from the fungus 
over which it has passed, it carries with it innumerable 
seeds of the disease, and destroys everything which oSers 
a bar to its progress. Air, in passing through damps, 
will partake of their humidity ; it therefore soon becomes 
inadequate to the task for which it is designed. Owing 
to this circumstance, air has been frequently admitted into 
the affected parts of a building without any ultimate 
success ; too often, instead of injuring the fungus, it has 
considerably assisted its vegetation, and infected with the 
disease other parts of the building, which would otherwise 
probably have remained without injury. The timber, 
which is in a state of decomposition by an intestinal 
decay, is little affected by the application of air, as this 
cannot penetrate the surrounding spongeous rottenness 
which generally forms the exterior of such timber, and 
protects the action which the humid particles have 
acquired in the exterior : as the extent and progress of 
the disease is therefore necessarily concealed, it is difficult 
to ascertain correctly the effect produced by the admission 



28 PREVENTION AND CURE OF 

of dry air. Under these circumstances of necessity and 
danger, it will require considerable skill to effect the 
purpose without increasing the disease, and, as each case 
has its own peculiar characteristics, it is necessary before 
one attempts to admit air as a remedy, to previously esti- 
mate the destructive consequences which may result from 
so doing, and ascertain whether it will be injurious or 
beneficial to the building. The joists of the houses built 
by our ancestors last almost for ever, because they are in 
contact with an air which is continually changing. Now, 
on the contrary, we foolishly enclose them between a 
ceiling of plaster (always very damp to begin with) and 
a floor; they frequently decay, and then cause the most 
serious disasters, of which it is impossible to be fore- 
warned. 

Damp, combined wdth warmth, is as a destroying agent, 
still more active than simple damp alone — the heat being 
understood as insufficient to carry off the moisture by 
evaporation ; and the higher the temperature with a cor- 
responding degree of moisture, the more rapid the decay. 
If the temperature to which wood is exposed, whilst any 
sap remains in it, is too elevated, the vegetable fluids 
ferment ; the tenacity is diminished, and when the action 
is carried to its full extent, the wood quickly becomes 
afiected by the dry rot. Exposure to the atmosphere 
in positions where rain can lodge in quantity, contact 
with the ground, and application in damp situations 
deprived of air, will render wood liable to the wet rot ; 
and however well seasoned it may have been previously 
to being brought within the influence of any of these 



DRY ROT IN TIMBER. 29 

causes, it will infallibly suffer. Air should therefore have 
free access to the wood in every direction : 

** for without in the waU of the house he made narrowed rests 

round about, that the beams should not be fastened in the waUa of the 
house." — 1 Kings vi. 6. 

Eondelet says, '' The woodwork of the church of St. 
Paul, outside the city walls, w^hich was destroyed by fire 
in 1823, was erected as far back as the fifth century." 
Although the atmosphere surrounding the framew^ork was 
often at once warm and damp, yet it was never stagnant. 
It should be remembered that 500 people in a church 
during two hours give off fifteen gallons of water into the 
air, which, if not carried aw^ay, saturates everything in 
the building after it has been breathed over and over 
again in conjunction with the impurities it contains col- 
lected from each individual. 

Fever, scrofula, and consumption arise in many instances 
from defective ventilation. 

The signs of decay in timber are, as has been stated, 
fungi. Some of them now and then are microscopic, and 
ow^e their existence to the sporules deposited on the 
surface ; while fermentation, generated by prolonged con- 
tact with warm, damp, and stagnant air, is as a soil where 
seeds sow and nourish themselves. 

Mr. McWilliam, in his work on dry rot, states that if 
the temperature be very low or very high, the effects are 
the same with respect to the growth of fungi. At 80° dry 
rot will proceed rapidly, at 90° its progress is more slow : 
at 100° it is slower still, and from 110° to 120° it will in 
general be arrested. It will proceed fast at 50° ; it may 



30 PREVENTION AND CURE OF 

be generated at 40° ; its progress will be slow at 36° ; and 
is arrested at 32°, yet it will return if the temperature is 
raised to 50°. 

Dry rot externally first makes its appearance as a 
mildew, or rather a delicate white vegetation, that looks 
like such. The next step is a collecting together of the 
fibres of the vegetation into a more decided form, some- 
w^hat like hoar frost ; after which it speedily assumes the 
leathery, compact character of the fungus, forming into 
leaves, spreading rapidly in all directions, and over all 
materials, and frequently ascending the walls to a con- 
siderable height, the colour variable — white, greyish white, 
and violet, light or decided brown, &c. 

In the section of a piece of wood attacked by dry rot 
a microscope reveals minute white threads spreading and 
ramifying throughout its substance ; these interlace and 
become matted together into a white cottony texture, 
resembling lint, which effuses itself over the surface of 
the timber ; then in the centre of each considerable mass 
a gelatinous substance forms, which becomes gradually of 
a yellow, tawny hue, and a wrinkled, sinuated porous con- 
sistence, shedding a red powder (the spores) upon a white 
down ; this is the resupinate pileus, the hymenium being 
upwards, of Merulius lachrymans, in its perfect and 
matured state. Long before it attains to this, the whole 
interior of the wood on which it is situated has perislied ; 
the sap vessels being gradually filled by the cottony 
filaments of the fungus ; no sooner do these appear 
externally than examination proves that the apparently 



DPvY ROT IN TIMBER. 31 

solid beam may be crumbled to dust between tlie fingers ; 
tenacity and weight are annihilated. 

Dr. Haller says that seven parts in eight of a fungus in 
full vegetation are found by analysis to be completely 
aqueous. 

The strength of fungi is proportionate to the strength 
of the timber the cohesive powers and nutritive juices of 
which they absorb ; and according to the food they receive 
so they are varied and modified in different ways, and 
are not always alike. Different stages of corruption pro- 
duce food of different qualities, and hence many of the 
diflerent appearances of fungi. One takes the process of 
corruption up where another leaves it off, and carries it 
forward and farther forward to positive putrefaction. 

The forms which fungi assume are extremely diversified; 
in some instances we have a distinct stem supporting a 
cap, and looking somewhat like a parasol ; in others the 
stem is entirely absent, and the cap is attached either by 
its margin, and is said to be dimidiate, or by its back, or 
that which is more commonly its upper surface, when it is 
called resupinate. In some species the form is that of a 
cup, in others of a goblet, a saucer, an ear, a bird's nest, a 
horn, a bunch of coral, a ball, a button, a rosette, a lump 
of jelly, or a piece of velvet. 

Decomposition takes place without fungus where the 
timber and the situation are always moist, as in a 
close-boarded kitchen floor, where it is always dry, or 
very nearly so, and where it is alternately wet and drj', 
cold and hot. When the decomposition is affected with 



32 PREVENTION AND CURE OF 

very little moisture, and no fungus, the admission of air 
will generally prevent further contamination; but where 
there is abundance of moisture, rottenness, and fungus, a 
small quantity of air will hasten the destruction of the 
building. 

In timber which has been only superficially seasoned 
this disease is produced internally, and has been known to 
convert the entire substance of a beam, excepting only 
the external inch or two of thickness to which the 
seasoning had penetrated, into a fine, white, and thread- 
like vegetation, uniting in a thick fungous coat at the 
ends, the semblance being that of a perfectly sound beam. 
In this internal rot a spongy fungous substance is formed 
between the fibres. Tliis has often been observed in large 
girders of yellow fir, which have appeared sound on the 
outside, but by removing some of the binding joists have 
been found completely rotten at the heart. An instance 
of this kind occurred at Kenwood (the seat of the Earl of 
Mansfield) in 1815. Major Jones, E.E., states that on one 
occasion he was called upon to report on the state of a 
building in Malta ; that the timbers had every external 
appearance of being sound, but on being bored with an 
auger they were found internally in a total state of decay. 
It is on this account that the practice of sawing and 
bolting beams is recommended, for when timber is large 
enough to be laid open in the centre this part is laid open 
to season ; so that when a tree is large enough to be cut 
through to make two or more beams, decomposition is 
impeded. 

The first symptoms of rottenness in timber are swelling, 



DRY ROT IN TIMBER. 33 

discoloration, and moiildiness, accompanied with a musty 
smell; in its greater advance the fibres are found to 
shrink lengthways and break, presenting many deep 
fissures across the wood ; the fibres crumble readily to a 
fiine snuff-like powder, but retain, when undisturbed, much 
of their natural appearance. 

In whatever way boughs are removed from trees, the 
effect of their removal is, however, very frequently to 
produce a rotting of the inner wood, which indicates 
itself externally by a sudden abnormal swelling of the 
trunk a little above the root; sometimes the trunk 
becomes hollow at the part affected, and this particular 
description of rot will almost invariably be found to exist 
in those trees whose roots are much exposed. The rot 
itself is either of a red, black, or white colour in the 
timber when felled, and when either of the two last- 
named colours prevail, it will be found that the decay 
does not extend very far into the tree; but if, on tlie 
contrary, the colour of the parts most visibly affected 
should be decidedly red, the wood should be rejected for 
any building purposes. Sometimes small brown spots, 
indicative of a commencement of decay, may be observed 
near the butt or root end of trees, and though they do 
not appear to be connected with any serious immediate 
danger to the durability of the wood, it is advisable to 
employ the material so affected only in positions where it 
w^ould not be confined in anything like a close, damp 
atmosphere. 

Great hesitation may be admitted as to the use of 
timber which presents large bands of what are supposed 



34 PREVENTION AND CURE OP 

to be indefinitely-marked annual growth, because the 
existence of zones of wood so affected may be considered 
to indicate that the tree was not in a healthy state when 
they were formed, and that the wood then secreted lacked 
some of the elements required for its durability, upon being 
subsequently exposed to the ordinary causes of decay. 

In many cases when timber trees are cut down and 
converted for use, it is found that at the junction of some 
of the minor branches with the main stem, the roots, as it 
were, of the branches traverse the surface wood in the 
form of knots, and that they often assume a commence- 
ment of decay, which in the course of time will extend to 
the wood around them. This decay seems to have arisen 
in the majority of cases from the sudden disruption of 
the branch close to its roots, with an irregular fracture, 
and with such depressions below the surface as to allow 
the sap to accumulate, or atmospheric moisture to lodge in 
them. A decomposition of the sap takes place — in fact, 
a wound is made in the tree — and what are called " druxy 
knots " are thus formed, which have a contagious action 
on the healthy wood near them. 

There is this particular danger about the dry rot ; viz. 
that the germs of the fungi producing it are carried easily, 
and in all directions, in a building wherein it once displays 
itself, without necessity for actual contact between the 
affected or the sound wood ; whereas the communication 
of the disease resulting from the putrefactive fermenta- 
tion, or the wet rot, only takes place by actual contact. 

Before dry rot has time to destroy the principal timbers 
in a building, it penetrates behind the skirtings, dadoes, 




'*fl 



1 



u 



win 



i 






\h 



,:, V< 



k 




f I 




Timber Beairui, — rcttert cub Uve tuuwi . 



DRY ROT IN TIMBER. 35 

and wainscotings, drawing in the edges of the boards, and 
splitting them both horizontally and vertically. When 
the fungus is taken off, they exhibit an appearance similar 
both in back and front to wood which has been charred ; a 
light pressure with the hand will break them asunder, 
even though affected with the rot but a short time ; and 
in taking down the wainscot, the fibrous and thin-coated 
fungus will generally be seen closely attached to the 
decayed wood. In timber of moderate length the fungus 
becomes larger and more destructive, in consequence of 
the matter congenial to its growth affording a more 
plentiful supply. 

It is a great characteristic of fungi in general that they 
are very rapid in growth, and rapid in decay. In a night 
a puff-ball will grow^ prodigiously, and in the same short 
period a mass of paste may be covered with mould. In a 
few hours a gelatinous mass of Beticularia will pass into 
a bladder of dust, or a Coprimis will be drippiug into 
decay. Many instances have been recorded of the rapidity 
of growth in fungi ; it may also be accepted as an axiom 
that they are in many instances equally as rapid in decay. 

In considering the liability of any particular description 
of foreign timber to take the dry rot, attention must 
be paid to the circumstances under which it is imported. 
Sometimes the timber is a long while coming here, whilst 
at other times it is imported in a very short period. The 
length of time consumed in the voyage has a great deal 
to do with its likelihood of taking the rot : it may have a 
very favourable passage, or a very wet one, and the ship is 
frequently, in some degree, affected with the disease. It 

D 2 



36 PREVENTION AND CURE OF 

perhaps begins in the ship, and it may often be seen 
between the timber or deals, when it will impregnate the 
wood to a great depth. Whether it is inherent in the 
timber or not, of this we may be certain, that where there 
is a fetid atmosphere it is sure to grow. Canadian yellow 
wood pine timber is more subject to rot than Baltic or 
Canadian red wood timber, although the latter will 
sometimes decay in four or five years. Turpentine is a 
preventive against dry rot, and Canadian timber is some- 
times largely impregnated with it, especially the red wood 
timber ; the yellow wood is very subject to dry rot. Very 
few cargoes of timber in the log arrive from Canada in 
which in one part or other of nearly every log you will 
not see a beginning of the vegetation of the rot. Some- 
times it will show itself only by a few reddish, discoloured 
spots, which, when scratched by the finger nail to the 
extent of each spot, it w^ill be seen that the texture of 
the timber to some little depth is destroyed, and will be 
reduced to powder ; and on these spots a white fibre may 
generally be seen growing. If the timber has been 
shipped in a dry condition, and the voyage has been a 
short one, there may be a few logs without a spot ; but 
generally speaking very few cargoes arrive from Canada 
in which there are many logs of timber not affected. But 
if the cargo has been shipped in a wet condition, and the 
voyage has been a long one, then a white fibre will be 
seen growing over nearly every part of the surface of 
every log ; and in cargoes that have been so shipped, all 
the logs of yellow pine, red pine, and of oak, are generally 
more or less affected on the surface. 



DRY ROT IN TIMBER. 37 

Nearly every deal of yellow pine that has been shipped 
in Canada in a wet state, when it arrives here is also 
covered over with a network of little white fibres, which 
are the dry rot in its incipient state. There is no cargo, 
even that which is shipped in tolerably dry condition, in 
which, upon its arriving here, may not be found some 
deals, with tlie fungus beginning to vegetate on their 
surface. If they are deals that have been floated down 
the rivers of America or Canada, and shipped in a wet 
state, on their arrival here they are so covered with this 
network of the fungus, that force is often necessary to 
separate one deal from another, so strongly does the 
fungus occasion them to adhere. They grow together 
again, as it were, after quitting the ship, while lying in 
the barges, before being landed. Accordingly, if a cargo 
has arrived in a wet condition, or late in the year, or if 
the rain falls on the deals before they are landed, and 
they are then piled in the way in which Norwegian and 
Swedish deals are piled, that is, flatways, in six months 
time, or even less, the whole pile of deals become deeply 
affected with rot ; so that, whenever a flat surface of one 
deal is upon the flat surface of another, the rot penetrates 
to the depth of I of an inch. Its progress is then arrested 
by repiling the deals during very dry weather, and by 
sweeping the surface of each deal before it is replied : but 
the best way is to pile the deals in the first instance upon 
their edges ; by which means the air circulates freely 
around them, the growth of the fungus is arrested, and 
the necessity of repiling them prevented. If the ship is 
built of good, sound, and well-seasoned oak, the rot would 



38 PREVENTION AND CUBE OF 

perhaps not affect it, but in order to prevent its doing so, 
the precaution is usually taken to scrape the surface as 
soon as the hold is clear of the cargo of timber. Were 
the cargo not cleared, and the hold not ventilated, a ship 
that was permanently exposed to this fungus would, no 
doubt, be affected. It is easy, however, to prevent its 
extending by washing the hold with any desiccating 
solution. 

Anyone who wishes to know how timber is occasionally 
shipped to this country should read the report of a trial, 
in the 'Times,' 22nd Feb., 1875 (Harrison v. Willis), 
relative to a cargo of pitch pine shipped from Sapelo, in 
the Isthmus of Darien, ^for Liverpool. This cargo, how- 
ever, never arrived at Liverpool : it was lost at sea. 

The motto of the Worshipful Company of Shipwrights 
is, "Within the ark, safe for ever." We suo'2:est it should 
be altered to, " Within the ark which is free from dry rot, 
safe for ever." 

There are two descriptions of European deals very 
liable to take the dry rot ; viz. yellow Petersburgh deals, 
and yellow and white battens, from Dram, in Norway. 
When Dram battens, which have been lying a long time 
in bond in this country, have not been replied in time, 
they have been found as much affected with the dry rot 
as many Canadian deals; though this has not happened 
in so short a time as has been sufficient to rot Canadian 
deals. The fungus growing on the Petersburgh deals and 
Dram battens has all the characteristics and effects of dry 
rot as exhibited in the Canadian deals, the detection of 
dry rot being in most cases the same. 



DRY ROT IN TIMBER. 39 

It should be remembered that white deal absorbs more 
water than yellow ; and yellow more water than red ; and 
the quantity of water absorbed by the white accounts for 
its more rapid decay in external situations ; as the greater 
the quantity of water absorbed the quicker is the timber 
destroyed. Mr. John Lingard, in his work on timber 
(1842), states that he has proved that 4|- oz. of water can 
be driven off from a small piece of fir, weighing only 
10 oz. wlien wet, which is nearly half. This timber was 
on a saw-pit, and going to be put into a building. 

The most general, and the most fatal cause of decay, 
viz. the wet rot, has attracted less attention than the more 
startling, but less common evils, the dry rot, and the 
destruction by insects. 

Sir Thomas Deane, in 1849, related before the Institu- 
tion of Civil Engineers of Ireland, an extraordinary 
instance of the rapid decay of timber from rot, which 
occurred in the church of the Holy Trinity at Cork. 

On opening the floors under the pews, a most extra- 
ordinary appearance presented itself. There were flat 
fungi of immense size and thickness, some so large as 
almost to occupy a space equal to the size of a pew, and 
from 1 to 3 inches thick. In other places fungi appeared, 
growing with the ordinary dry rot, some of an unusual 
shape, in form like a convolvulus, with stems of from a 
quarter to half an inch in diameter. When first exposed, 
the whole was of a beautiful buff colour, and emitted the 
usual smell of the dry-rot fungus. 

During a great part of the time occupied in the repairs 
of the church, the weather was very rainy. The arches 



40 PREVENTION AND CURE OF 

of the vaults having been turned before the roof was 
slated, the rain water saturated the partly decayed oak 
beams. The flooring and joists, composed of fresh timber, 
were laid on the vaulting before it was dry, coming in 
contact at the same time with the old oak timber, which 
was abundantly supplied with the seeds of decay, stimu- 
lated by moisture, the bad atmosphere of an ill- contrived 
burial-place, and afterwards by heat from the stoves con- 
stantly in use. All these circumstances account satisfac- 
torily for the extraordinary and rapid growth of the fungi. 

Many instances might be mentioned of English oak 
being affected with dry rot, under particular circum- 
stances. There was a great deal at the Duke of Devon- 
shire's, at Chiswick, about 60 years ago. Needy builders, 
who work for contract, sometimes use American oak, and 
call it wainscot : it is a bad substitute for wainscot, being 
very liable to warp and to be affected with dry rot. " I 
know of one public building," observed the late Mr. Henry 
Warburton, M.P., '^ in which it has been introduced, and, 
I suppose, paid for under that name." 

Another serious instance of the decay of timber from 
rot occurred some time since in Old St. Pancras Church, 
London. When the dry rot made its appearance, it 
spread with amazing rapidity. Sometimes in the course 
of a night, a fungus of about the consistence of newly- 
fallen snow, and of a yellowish - white unwholesome 
colour, would be found to have spread over a considerable 
surface. The fungus was without shape, but in some cases 
it rose to a height of 2, 3, or 4 inches above the planks 
or other surfaces on which it grew. It could be cut with 



DRY ROT IN TIMBER. 41 

a knife, leaving a clear edge on each side, and there did 
not seem to be any covering or membrane over the outer 
or under surface. The smell of those matters was un- 
pleasant, and seemed like the concentration of the smell 
which had pervaded the church for so long a time before ; 
and, in a short time, beams, planks of flooring, railings, &c., 
were reduced to rottenness : the colour changed, and a 
heavy dark-brown dust fell, and represented the once 
solid timber. On making an examination with a view of 
discovering the cause of the attack, it was found that in 
the graveyard, near the church, there were graves, and 
several vaults: there were also vaults in the inside of 
the church. Most of them were filled, or nearly so, with 
water, which had run from the overcrowded graves. 

In the interior there were water-logged vaults, and the 
walls were saturated with damp. It was also seen that 
from want of proper spouts and drains, near the outer 
walls, the drip from the large pent roof had fallen into 
the foundations. In this situation, when the window 
frames were properly arranged, a drain dug round and 
from parts of the church, and other alterations, which 
should long before have been made, were completed, the 
dry rot vanished, and no more complaints of the foulness 
of the air have since been heard. 

We could quote many cases of rot w^hich have been 
caused from the want of proper drains and spouts. Archi- 
tects should remember that the feet of Gothic collar roofs 
have to bear the whole weight of the roof, and unless well 
seasoned, and carefully protected from damp, leaks, &c., 
premature decay and dry rot will be sure to occur. It is 



42 PREVENTION AND CURE OF 

surprising what injury leaks from gutters will sometimes 
do. In 1851, Professor T. L. Donaldson stated that " a 
brestsummer of American timber Avas used some time 
since at a house in London : after an expiration of three 
years cracks began to appear in the front wall. A friend 
of mine, an architect, was called in to find out the cause ; 
and after examining different parts of the house, was 
almost giving up his search in despair, when he thought 
he would have the shop cornice removed and look at the 
brestsummer. He then discovered that some water had 
been admitted by accident, and penetrating the brest- 
summer, had caused it to rot, and crack the wall." 

Dry rot was found in the great dome of the Bank of 
England, London, as originally built by Sir Eobert 
Taylor : it also existed in the Society of Arts building, in 
the Adelphi, London. It was also found in the domes of 
the Pantheon, and Halle-au-Ble, Paris ; but we hope there 
is no dry rot in the dome of St. Paul's Cathedral, London, 
which is constructed entirely of timber, covered externally 
with lead. 

The decayed state of a barn floor attacked by rot is 
thus described by Mr. B. Johnson : '^ An oak barn floor 
which had been laid twelve years began to shake upon 
the joists, and on examination was found to be quite 
rotten in various parts. The planks, 2^ inches in thick- 
ness, were nearly eaten through, except the outsides, 
which were glossy, and apparently without blemish. The 
rotten wood was partly in the state of an impalpable 
powder, of a snuff colour ; other parts were black, and the 
rest clearly fungus. No earth was near the wood." This 



DRY ROT IN TBIBER. 43 

oak was probably of the Querciis sessilijlora species ; and 
there was no ventilation to the floor. 

Mr. John Armstrong, carpenter, employed for many 
years at Windsor Castle, observed : '' I was employed a 
few years back at a house where I found a floor rotten. 
We took it up ; it was yellow pine ; it was laid in the 
damp, but on sleepers, and the sleepers were not rotten : 
they were of a different description of wood." Probably 
the sleepers were of Baltic red wood. 

Dr. Carpenter relates an instance of the expansive 
power resulting from the rapid growth of the soft cellular 
tissue of fungi. About the commencement of this cen- 
tury the town of Basingstoke w^as paved ; and not many 
months afterwards the pavement was observed to exhibit 
an unevenness which could not easily be accounted for. 
In a short time after, the mystery was explained, for some 
of the heaviest stones were completely lifted out of their 
beds by the growth of large toadstools beneath them. 
One of these stones measured 22 inches by 21 inches, 
and weighed 83 lb., and the resistance afforded by the 
mortar which held it in its place would probably be even 
a greater obstacle than the weight. A similar incident 
came under the notice of Mr. M. C. Cooke (the author of 
'British Fungi'), of a large kitchen hearthstone which 
was forced up from its bed by an under-growing fungus, 
and had to be relaid two or three times, until at last it 
reposed in peace, the old bed having been removed to the 
depth of 6 inches, and a new foundation laid. A circum- 
stance recorded by Sir Joseph Banks is still more extra- 
ordinary, of a cask of wune which, having been confined 



44 PREVENTION AND CURE OF 

for three years in a cellar, was, at the termination of that 
period, found to have leaked from the cask, and vegetated 
in the form of immense fungi, which had filled the cellar, 
and borne upwards the empty wine cask. 

Timber decay in contact with stone is a subject deserv- 
ing consideration. :This decay is entirely obviated by 
inserting the wood in an iron shoe, or by placing a thin 
piece of iron between the wood and the stone. It is said 
that a hard crust is formed on the timber in contact with 
the iron, which seems effectually to preserve it ; it is, of 
course, necessary that a free circulation of air round the 
ends of the timber be provided. The most notable 
instance of timber decay in contact with stone with 
which we are acquainted occurred at the coronation of 
George IV. Westminster Hall was then fitted up, and 
they began by laying sleepers of yellow pine. The coro- 
nation was suspended for twelve months, and when the 
sleepers were taken up from the floor of Westminster 
Hall, they were in a rotten state. 

Timber in contact with brickwork is in Suffolk and in 
some parts of England covered with sheet lead to preserve 
it from the effects of the damp mortar. Fungi will arise 
in mortar, if made with road-drift, and water from stagnant 
ponds, &c., and it may be traced through the mortar 
joints, and will thus appear on both sides of a wall. 
Mortar composed of unwashed sand will generate fungi ; 
sea sand, even if washed, should never be used. It is 
considered that the system of grouting contributes to 
the early decay of timber; wood bond timber for walls 
has been consequently replaced by hoop iron bond. In 



DRY ROT IN TIMBER. 45 

Manchester wood bond is frequently used, and is said 
to answer well, but the high temperature of the buildings 
may be a preventive against the decay of timber, as the 
walls are soon dried. The practice is a bad one. 

When timber used as posts inserted in the ground is 
placed in the inverted position to that in which it stood 
when growing, it is said to be very much more durable 
than if placed in its natural or growing position. This is 
easily accounted for in the valves of the sap vessels of the 
growing timber opening upwards ; but when that position 
is inverted, the valves of the sap vessels become reversed 
in their action ; and, therefore, when timber is used as 
posts inserted in the ground, the valves being so reversed 
prevent the ascent of moisture from the soil in the wood. 
Mr. W. Howe relates an experiment made to test the com- 
parative durability of posts set as they grew. He says, 
" Sixteen years ago I set six pairs of bar posts all split 
out of the butt end of the same white oak log. One pair I 
set butts down ; another pair, one butt down, the other top 
down; the others top down. Four years ago those set 
butt down were all rotted off, and had to be replaced by 
new ones. This summer I had occasion to reset those 
that were set top down : I found them all soiind enough 
to reset. My experiments have convinced me that the 
best way is to set them tops down." Other instances 
might be given in favour of placing posts in an inverted 
position in the ground. Posts will sometimes decay, for 
the following reason : The ends are often sawn off with a 
coarse implement and left spongy, with the longitudinal 
fibres shaken or broken a considerable wav within the 



46 PREVENTION AND CURE OF 

extremity of the wood. In this state the ends of the posts 
must be apt to absorb from the ground the moisture, 
which, being retained, and speedily pervading the whole 
internal surface, especially if painted, appears to cause 
decay. 

With respect to the preservation of wooden fences, Mr. 
Cruikshank, of Marcassie, gives in detail various experi- 
ments from which it appears that — 1st. When larch or 
pine wood is to be exposed to the weather, or to be put in 
the ground, no bark should be left on. 2nd. When posts 
are to be put in the ground, no earth should be put round 
them, but stones. 3rd. When a wooden fence is to be 
put up, a No. 4 or No. 5 wire should be stretched in place 
of, or alongside the upper rail. 

Mr. Gr. S. Hartig, in the ^ Eevue Horticole,' gives the 
results of experiments made with great care and patience^ 
upon woods buried in the earth. Pieces of wood of various 
kinds 3ith inches square, were buried about one inch 
below the surface of the ground, and they decayed in the 
following order : the lime, American birch, alder, and 
the trembling-leaved poplar, in three years ; the common 
willow, horse-chestnut, and plane, in four years ; the maple, 
red beech, and common birch, in five years ; the elm, ash, 
hornbeam, and Lombardy poplar, in six years ; the oak, 
Scotch fir, Weymouth pine, and silver fir, were only de- 
cayed to the depth of half an inch in seven years ; the 
larch, common juniper, red cedar, and arbor vitaB, at the 
end of the last-mentioned period remained uninjured. The 
duration of their respective woods greatly depends on their 
age and quality; specimens from young trees decaying 



DRY ROT IN TIMBER. 47 

much quicker than those from sound old trees ; and, \vhen 
well seasoned, they, of course, last much longer than when 
buried in an unseasoned state. In experiments with the 
woods cut into thin boards, decay proceeded in the follow- 
ing order : the plane, horse-chestnut, poplar, American 
birch, red beech, hornbeam, alder, ash, maple, silver fir, 
Scotch fir, elm, Weymouth pine, larch, locust oak. 

Before quitting the subject of decay of timber when 
buried in the earth, it will not be out of place to allude 
to the decay of raihvay sleepers, taking for example those 
in India : English and American sleepers will be dealt 
with more in detail hereafter. 

Dr. Cleghorn, Conservator of Forests, Madras Presi- 
dency, India, considers the decay of sleepers to arise in a 
great measure from the inferior description of wood used. 
Mr. Bryce McMaster, Eesident Engineer, Salem, con- 
siders that the native wood sleepers in India have hitherto 
been found for the most part to fail on the Madras Eail- 
w^ay, between 30 and 40 per cent, requiring to be renewed 
annually. Mr. McMaster undertook an investigation with 
a view of ascertaining the causes of this deterioration, and 
whether those causes could be overcome so as to render 
available the vast resources of India. Thirteen hundred 
sleepers of sixteen difierent woods were submitted to care- 
ful examination and scrutiny twice at an interval of one 
year. The sleepers were variously placed, both on em- 
bankments and in cuttings ; in some cases they were 
entirely covered with ballast to a depth of 4 inches; 
while in others they were as much as possible uncovered, 
and completely so from the rails to the ends — the ballast 



•48 PREVENTION AND CURE OF 

being only raised 2 inches in the middle of the way, 
and sloped off so as to carry away the water under the 
rails. From these observations it appeared that only five 
woods, Chella wunge, Kara marda, Palai, Kariivalem, and 
Ilupe, were sound at the end of two years, the other eleven 
not lasting even that time. Also, that when the sleepers 
were uncovered, decay was less rapid than when they were 
buried in the ballast. The plan of leaving the sleepers 
partially uncovered had many advantages; it effected a 
saving of the ballast, allowed the defects to be more quickly 
detected, and kept the sleepers drier. It had been urged 
that the heat of the sun would split the sleepers and cause 
the keys and treenails to shrink'; but from experience it 
was found that while among the " uncovered " sleepers 
there was a large proportion "beginning to split," or 
" useless from being split," there was on the other hand, 
among the " covered " sleepers, a still larger proportion 
" beginning to rot," or " useless from being rotten." It was 
also noticed that of the sleepers " beginning to rot," 19 per 
cent, had commenced under one or both chairs. This was 
due to the retention of moisture under them, and misfht 
be remedied by tarring the seats of the chairs. As re- 
garded the treenails where the sleepers were rotten, the 
treenails were invariably found to be in the same state ; 
while, when the heads were exposed to the sun, they were 
not loosened by shrinking. Another objection was, that 
the road would be more likely to buckle and twist, but 
this was not found in practice to be the case. Treenails 
made in India cost 2Z. 10s. to 4Z. per 1000, and the w^oods 
generally used for the purpose are Venge, Kara marda, 



DRY EOT IN TIMBER. 49 

Erul, Porasa, or satin wood, and Trincomalee. The three 
woods first named are also extensively employed for keys, 
but teak keys seem to be the best, and their cost does not 
exceed 61, per 1000. From the experience of the Indian 
engineers it appears that Teak, Saul, Sisso, Pedowk, Kara 
marda, Acha, Venge, Chella wunge, Palai, Erul, Karuva- 
lem, will make very good sleepers to be used plain. 

The sleepers which have failed on the Madras Eailway 
might well be divided into two classes, — those which were 
originally of perishable woods, and were therefore unfit for 
the purpose ; and those which although of good wood had 
been cut from young trees, and not been allowed to stand 
until old enough. The first arose from want of experience 
of the nature of Indian woods: the second from the absence 
of a proper system of working the jungles. 

The wooden sleepers on the Indian railways should be 
tarred under the seats of the chairs, be laid in dry ballast, 
and raised slightly in the middle, and sloped off so as to 
throw the water under the rails. About two-thirds of the 
Indian woods are practically useless owing to the want of 
proper artificial means for preserving those of a perishable 
nature. 

The subject of the decay of wood in India and tropical 
climates is too extensive to be further considered here ; 
but is of sufiicient importance to demand a volume to 
itself; the renewal of decayed wooden sleepers to railways 
forming annually a most important item in foreign rail- 
way budgets. 

We have heard that some of our fortifications which 
have been erected within the last few years to protect our 



50 PREVENTION AND CURE OP 

English coast from invasion, have already been invaded 
by dry rot. If this be true, some one well acquainted 
with the subject should at once be appointed to find out 
the cause, and recommend the remedy in each case. 

Professional men, if they wish their works to " live for 
ever," should consider the after consequences of neglect- 
ing to provide against dry rot. If the fungi could speak 
from under floors, ceiled - up roofs, behind wainscots, 
girders, &c., we should often hear them exclaim, " A nice 
moist piece of wood ! Surely this belongs to us." On the 
beams of a building at Crawley, a carpenter many years 
ago cut a few words ; they are full of meaning in con- 
nection with our subject, and they run as follows : 

" Man of weal, beware ; beware before of what cometh behind." 



DRY EOT IN TIjIBER. 51 



CHAPTER III. 

FELLING TIMBER. 

The end to be attained in the management of timber 
trees is to produce from a given number the largest 
possible amount of sound and durable woods. When a 
tree, under conditions favourable to its growth, ceases 
increasing the diameter of its trunk, and loses its foliage 
earlier in the autumn than it is wont to do, and when the 
top of the tree brings forth no leaves in spring, these 
facts may be considered as indications of decline, and that 
the tree is of sufficient age to be felled. The state of the 
upper branches of a tree may be considered to be amongst 
the best indications of its soundness, and provided they be 
in a healthy condition, the withering of the lower branches 
is a matter of comparatively small importance. 

Trees may be considered as tall, middle rank, and low, 
and the size to which they will attain depends on many 
different circumstances. Some trees, the stems of which 
are short on the average, as the lime, are virtually of tall 
growth, from the manner in which a number of vertical 
branches of large size ascend from the stem. And otlier 
trees, again, whose branches are comparatively short, are 
of tall growth, in consequeuce of the length of the stems 
— like the beech. 

The average duration of trees differs, as is well known, 

E 2 



52 PREVENTION AND CURE OF 

iu different species, and they exhibit different symptoms of 
decay. There are oaks in Windsor Great Park, certainly 
nearly one thousand years old, and which exhibit even now 
no appearance of approaching the end of their life. Mr. 
Menzies, the surveyor, in his work on ^Yindsor Great 
Park, describes some of the indications of incipient decay 
which are peculiar to the several kinds of trees. " When a 
beech begins to fail," he says, " fungi appear either at the 
roots or on the forks, the leaves curl up as if they had 
been scorched, and the tree quickly perishes. In an elm, 
a great limb first fails, while the rest of the tree continues 
green and vigorous, but in a few years the whole tree 
suddenly dies. Coniferous trees die gradually, but quickly 
The oak shows the first symptoms at the points of its 
highest branches, while the rest of the tree will remain 
healthy and sound far years." This peculiarity of the 
oak did not escape the eye of Shakespere, that universal 
observer, who describes the monarch of the woods as 
not only having its boughs mossed with age, but its 

** High top bald with dry antiquity.*' 

The age for felling trees is a subject w^hich calls for the 
deepest consideration, but does not always receive that 
attention which is due to its importance. Timber growers 
in their haste to supply the market, too often fell trees 
that have not arrived at maturity, the heart-wood being 
therefore imperfect, with much sap-wood, and, of course, 
little durability; but unfortunately they are the more 
readily led to do so on account of the increase in size 
being very slow after a certain age. Builders are sensible 



DRY ROT IN TIMBER. 53 

of the inferior quality of young timber in respect to dura- 
tion, and it is their province to check this growing 
evil, by giving a better price for timber that lias 
acquired a proper degree of density and hardness ; but, 
unfortunately, this is an age for cheap building, without 
much regard being given as to durability. 

Felling should not be too early, for the reasons above 
mentioned ; neither should it be in the decline of the tree, 
when its elasticity and vigour are lost, and the wood 
becomes brittle, tainted, and discoloured, with the pith 
gone, and the heart in progress of decay. Maturity is the 
period when the sap-w^ood bears a small proportion, and 
the heart-wood has become uniform and compact. Sir 
John Evelyn wastes, ^' It should be in the vigour and per- 
fection of trees, that a felling should be celebrated." It 
must be obvious, however, that it is a w orse fault to fell 
wood before it has acquired thorough firmness, than when 
it is just in the wane, and its heart may exhibit but the 
first symptoms of decay ; for in the former there is no 
perfect enduring timber to be got, while in the latter the 
greater part is in the zenith of its strength. 

Although there are certain symptoms by which it may 
be ascertained when a tree is on the decline, it is some- 
what difficult to decide just when a tree is at maturity. 
From the investigations of naturalists, however, it may be 
safe to consider that hard-wood trees, as oak and chestnut, 
should never be cut before they are sixty years old, the 
average age for felling being from eighty to ninety years, 
and the average quantity of timber produced by a tree of 
that ai^e is about a load and a half, or about 75 cubic feet. 



54 PREVENTION AND CURE OF 

Daviller states (see ^Cours d' Architecture ') "that an 
oak should not be felled at a less age than sixty years." 
Belidor considers (see ^Sciences des Ingdnieurs') "that 
one hundred years is the best age for the oak to be 
felled." 

It should be remembered that the times mentioned are 
by no means arbitrary, for situation, soil, &c., have much 
to do with it. For the soft woods, as the Norway spruce 
and Scotch pine in Norway, the proper age is between 
seventy and one hundred years. The ash, larch, and elm, 
may be cut when the trees are between fifty and ninety 
years old ; and between thirty and fifty years is a proper 
age for poplars. 

The felling of timber was looked upon by ancient 
architects as a matter of much moment. According to 
yitruvius, the proper time for felling is between October 
and February, and he directs that the trees should be cut 
to the pith, and then suffered to remain till the sap be 
drained out. The effusion of the sap prevents the decay 
of the timber, and when it is all drained out, and the wood 
becomes dry, the trees are to be cut down, when the 
wood will be excellent for use. A similar effect might be 
produced by placing the timber on its end as soon as it is 
felled, and it would, no doubt, compensate for the extra 
expense by its durability in use. In France, so long ago 
as 16G9, a royal order limited the felling of naval timber 
from the 1st October to 15th April, when the "wind was 
at north," and " in the wane of the moon." Buonaparte 
directed that the time for felling naval timber should be 
" in the decrease of the moon, from 1st November to 15th 
March," in order to render it more durable. In England, 



DRY ROT IN TIMBER. 55 

in the first year of James I., there was an Act of Parlia- 
ment prohibiting every one from cutting oak timber, 
except in the barking season, under a severe penalty. 

James I. was not the only English sovereign who has 
been concerned with timber trees; for King John was 
obliged to cancel at Eunnemede the cruel forest laws 
enacted by his father, William the Conqueror, especially 
those restricting the people from fattening their hogs. 

Up to a recent period large droves of hogs were fat- 
tened upon the acorns of the New Forest in Hampshire. 
At the present time the hogs of Estremadura are prin- 
cipally fed upon the acorns of the Ballota oak; and to 
this cause is assigned the great delicacy of their flesh. 

A Berkshire labourer, living near Windsor Forest, thus 
speaks of the delicacy of acorn-fed pork : " Well, that be 
pretty like the thing. I han't tasted the like o' that tlys 
many a day. It is so meller — when you gets your teeth 
on it, you thinks you has it ; but afore you knows where 
you is, ain't it wanished ! " 

There is another point in connection with the time of 
felling timber, which ought to be noticed. It is a wide- 
spread opinion that trees should be felled during the wane 
of the moon. This planetary influence is open to doubt, 
but the opinion prevails wherever there are large forests. 
Columella, Cato, Vitruvius, and Pliny, all had their 
notions of cutting timber at certain ages of the moon. 
The wood-cutters of South America act upon it, so do 
their brethren in the German forests, in Brazil, and in 
Yucatan. It was formerly interwoven in the Forest Code 
of France, and, we believe, is so still. Vitruvius recom- 
mends this custom, and we find Isaac Ware writing of the 



56 PREYENTIOX AND CURE OF 

suggestion : '^ This has been laughed at, and supposed 
to be an imaginary advantage. There may be good in 
following the practice ; there can be no harm : and there- 
fore, when I am to depend upon my timber, I will observe 
it." The Indian wood-cutters believe that timber is 
much more liable to decay, if cut when the moon is in 
crescent. 

An American writer, in 1863, thus writes of his ex- 
perience in the matter : " Tradition says that the ^ old ' 
of the moon, in February, is the best time to cut timber ; 
but from more than twenty years of observation and 
actual experience, I am fully convinced it is about the 
worst time to cut most, if not all kinds of hard-wood 
timber. Birch, ash, and most or all kinds of hard 
wood will invariably jyowder-post if cut any time in the fall 
after the tree is frozen, or before it is thoroughly leaved 
out in the spring of the year. But if cut after the sap in 
the tree is used up in the growth of the tree, until freezing 
weather again comes, it will in no instance produce the 
poivder-post worm. When the tree is frozen, and cut in 
this condition, the worm first commences its ravages on 
the inside film of the bark, and then penetrates the wood 
until it destroys the sap part thereof. I have found the 
months of August, September, and October, to be the 
three best in the year to cut hard-wood timber. If cut in 
these months, the timber is harder, more elastic, and 
durable than if cut in winter months. I have, by weigh- 
ing timber, found that of equal quality got out for joiners' 
tools is much heavier when cut and got out in the above- 
named months than in the winter and spring months, 



DKY ROT IN Ti:\rBER. 57 

and it is not so liable to crack. You may cut a tree in 
September, and another in the ' old ' of the moon in 
February following, and let them remain, and in one year 
from the cutting of the first tree, you will find it sound 
and unhurt, while the one last cut is scarcely fit for fire- 
wood, from decay. Chestnut timber for building will last 
longest, provided the bark be taken off. Hemlock and 
pine ought to be cut before being hard frozen, although 
they do not powder-post ; yet if they are cut in the middle 
of winter, or in the spring of the year, and the bark is 
not taken off, the grub will immediately commence its 
ravages between the bark and the w ood. I have walnut 
timber on hand which has been cut from one to ten years, 
with the bark on, whicli was designed for ox-helves and 
ox-bows, and not a worm is to be found therein ; it was 
cut between 1st August and 1st November. I have other 
pieces of similar timber cut in the winter months, not two 
years old, and they are entirely destroyed, being full of 
powder-post and grub-worms." 

What shall we say when doctors disagree ? The theory 
given to account for what is assumed to be a fact, is, that 
as the moon grows the sap rises, and the wood, therefore> 
is less dense than when the moon is waning, because at 
that time the sap in the tree diminishes. No evidence 
whatever can be offered in support of the theory, and one 
would certainly imagine that the rise or fall of the sap 
would depend on the quantity of heat which reaches tlie 
foot of the tree, and not at all on attraction. 

All investigations tend to prove that the only proper 
time for felling timber is that at which the tree contains 



58 PREVENTION AND CURE OF 

the least sap. There are two seasons in each year when 
the vessels are filled. One is in spring, when the fluid is 
in motion to supply nutriment to the leaves, and deposit 
material for new wood ; the other is in the early part of 
autumn, when, after the stagnation which gives the new 
wood time to dry and harden, it again flows to make the 
vegetable deposits in the vessels of the wood. At neither 
of these times should trees be felled ; for, if the pores be 
full of vegetable juices, which being acted upon by heat 
and moisture may ferment, the wood will decay. Of the 
two periods, the spring must be the worst, because the 
wood then contains the greatest quantity of matter in a 
state fit for germination. 

The results of a series of experiments made in Germany 
show that December-cut wood allows no water to pass 
through it longitudinally; January-cut wood passed in 
forty-eight hours a few drops ; February-cut wood let two 
quarts of water through its interstitial spaces in forty- 
eight hours ; March-cut wood permitted the same to filter 
through in two and a half hours. Hence the reasons 
why barrels made from wood cut in March or April are 
so leaky, as the sap is then rising, and the trees are 
preparing to put forth their leaves. 

It thus happens that the time for felling is midsummer 
or midwinter. The best time for felling, according to 
some, is midsummer, when the leaves are fully expanded, 
and the sap has ceased to flow, and the extraneous vege- 
table matter intended for the leaves has been dislodged 
from the trunk of the tree by the common sap, leaving it 
in a quiescent state, and free from that germinative prin- 



DRY ROT IN TIMBER. 59 

ciple which is readily excited by heat and moisture, and 
if the timber were cut while it remained, would subject it 
to rapid decay and to operations of worms. Midwinter, 
amongst some, is chosen as a time for felling, as it is 
stated that winter-felled heart-wood is less affected by 
moisture, and likely to be the best and most durable ; but 
as the only peculiar recommendation which that time 
possesses is the facility w^hich it affords for gradual 
seasoning, by which timber is rendered less liable to split 
and get distorted, and slow drying being generally avail- 
able at any season under shade and shelter, midsummer 
appears for many obvious reasons the most expedient. 
In general, all the soft woods, such as elm, lime, poplar, 
willow, should be felled during winter. In some kinds of 
trees a little after midsummer appears to be decidedly 
the best time for felling. Alder felled at that time is 
found to be much more durable ; and Ellis observes, that 
beech when cut in the middle of summer is bitter, and 
less liable to be worm-eaten, particularly if a gash be cut 
to let out the sap some time before felling. Mr. Knowles 
states that, " About Naples, and in other parts of Italy, 
oaks have been felled in summer, and are said to have 
been very durable." Most of the trees in southern Italy 
are felled in July and August, and the pines in tho 
German forests are cut down mostly in summer time, and 
it is stated that their wood is sound. 

The following are advocates for winter felling, viz. 
Cato, Pliny, Vitruvius, Albert i, Hesiod, De Saussure, 
Evelyn, Darwin, and Buonaparte. Some of them consider 
that winter-felled timber, which has been barked and 



60 PKEVENTION AND CURE OF 

notched in the previous spring, loses much of that half- 
prepared woody matter, containing seeds of fungi, &c., that 
there is no doubt of its superiority to summer-felled timber. 

The age at which trees should be felled, and the most 
suitable time for the work having been determined, there 
are two other things which claim attention. 

The first of these is the removal of the bark from the 
trunk and principal branches of the tree. For, in oak 
trees, the bark is too valuable to be lost ; and as the best 
period for the timber is the worst for the bark, an in- 
genious method has been long partially practised, which 
not only secures the bark at the best season, but also 
materially improves the timber. This method consists in 
taking the bark off the standing tree early in the spring, 
and not felling it till after the new foliage has put forth 
and died. This practice has been considered of inestimable 
value ; for by it the sap-wood is rendered as strong and 
durable as the heart- wood; and in some particular in- 
stances experiments have shown it to be four times as 
strong as other wood in all respects similar, and grown 
on the same soil, but felled with the bark on and dried in 
sheds. Buffon, Du Hamel, and, in fact, most naturalists, 
have earnestly recommended the practice. Evelyn states, 
" To make excellent boards, bark your trees in a fit season, 
and let them stand naked a full year before felling." 

In regard to the time that should elapse between the 
removal of the bark and the felling of a tree, a variety of 
opinions exist. It was the usual custom of early archi- 
tects to remove the bark in the spring, and fell the trees 
during the succeeding winter. Later investigations seemed 



DRY EOT IN TIMBER. Gl 

to have proved that it is better to perform the work three 
or even four years in advance, instead of one, although 
Tredgold appears to think one year too long. Trees will, 
in most situations, continue to expand and leaf out for 
several seasons after the bark has been removed. The 
sap remaining in the wood gradually becomes hardened 
into woody substance, thereby closiug the sap vessels and 
making it more solid. As bark separates freely from the 
wood in spring, while the sap is in motion, it should be 
taken off at that period. When the above method is not 
adopted, it is well either to pierce the trunk some time 
before felling to drain out the sap, or immediately on its 
being felled to set it on end. 

The second suggestion is, to cut into and around the 
entire trunk of the tree, near the roots, so that the sap 
may be discharged ; for in this manner it will be done 
more easily than it can be by evaporation after the tree 
is felled. In addition to this, if it be permitted to run 
out at the incision, a large portion of the new and ferment- 
able matter will pass out with it, which would remain in 
the wood if only such material is removed as would pass 
off by evaporation. This cutting should be made in the 
winter previous to the August in which the tree is to be 
felled ; and the incision should be made as deep into the 
heart-wood as possible without inducing a premature fall 
of the tree. 

The custom of ringing or girdling the tree before felling 
has been advocated, on the ground that the seasoning is 
thereby expedited, and also more thoroughly effected. 
This is doubtful, at least, in oil-containing trees (as teak, 



62 PREVENTION AND CURE OF 

&c.), but the practice appears to be contra-indicated for 
other reasons : when a tree has been ringed, many wood- 
cutters object to cut it down on account of its increased 
hardness. This objection might be waived, were it not for 
another and more serious one w^iich has been adduced. 
It is believed to be a fact by some that trees felled after 
girdling have the heart shake increased. It is difficult 
to explain this, if it be actually the case. 

Many suggestions might be made as regards the me- 
chanical operation of felling trees, with which ancient 
nations were not unfamiliar : 

"for tliou knowest that there is not among us any that can skill 

to hew timber like unto the Sidonians." — 1 Kings v. 6. 

But as these operations are familiar to all intelligent 
workmen, it is only necessary to mention one, viz. the 
value of removing from the side of the tree such branches 
as will strike the ground when it falls, and, by wrenching, 
cleave the grain of the wood, and thereby injure the 
timber. Such defects, which are often found after the 
timber has been seasoned, could not be discovered when it 
left the mill. 

In conclusion, we can truly state that the most exten- 
sive felling of trees for one huilding only which we have 
ever heard or read of is the following : 

*' And Solomon had threescore and ten thousand that bare burdens, and 
fourscore thousand hewers in the mountains." — 1 Kings v. 15. 



DRY EOT IN TIMBER. G3 



CHAPTER IV. 

ON SEASONING TIMBER BY NATURAL METHODS, VIZ. HOT 
AND COLD AIR ; FRESH AND SALT WATER ; VAPOUR ; 
SMOKE; STEAM; BOILING; CHARRING AND SCORCH- 
ING, ETC. 

All timber must, whetlier it be sap-wood or heart-wood, 
be placed in situations which will allow the sap to exude or 
evaporate, and this process is the one technically known 
by the term " seasoning." There are natural and artificial 
modes of seasoning, both of which have their recom- 
mendations ; but the former has certainly the right of 
preference, as it gives greater toughness, elasticity, and 
durability, and therefore should alvvays be employed in 
preparing timber for carpentry. As the w^ord " timber " 
has been frequently used, it may be as well to state that 
it is derived, according to Dr. Johnson, from the Saxon, 
timhrian, to build : hence the above definition. The legal 
definition of timber is restricted to particular species of 
wood, and custom varies in different countries as to the 
species ranked among the timber trees. 

When a tree is felled, it encloses in its fibres as well as 
in capillary channels a considerable quantity of sap, 
which is nothing else but water charged with gummy, 
saccharine, saline, mucilaginous, and albuminous matters. 
In this state, the latter are very liable to ferment, but 
they lose their liability when, by the evaporation of the 



64 PREVENTION AND CURE OF 

sap, they pass to a dry and solid state ; so that the first 
suggestion ^yhich naturally presents itself to the mind, is 
to subject the timber to a lengthened seasoning. 

But the present demands for time will not admit of 
this, and therefore it is imperative to resort to artificial 
and speedy methods. 

With respect to the value of timber in the log, owing 
to its becoming rent by the weather, it sells for 15 per 
cent, less the second year than the first, and so on for less 
and less the longer you keep it. 

A natural seasoning may be adopted for specimens of 
moderate thickness, such as deals, planks, &c. At the 
end of eighteen months from the time of importation 
they are scarcely dry enough for the consumer's use. 

When there is time for drying it gradually, all that is 
necessary to be done on removing it from the damp ground 
of the forest, is to place it in a dry yard, sheltered from 
the sun and wind, and where there is no vegetation ; and 
set it on bearers of iron or brick in such a manner as to 
admit of a ventilation all round and under it. In this 
manner it should continue two years, if intended for 
carpentry ; and double that time, if intended for joinery ; 
the loss of weight which should take place to render it 
fit for the purposes of the former being about one-fifth ; 
and for the latter about one-third. In piling it, the 
sleepers on which the first pieces are laid should be per- 
fectly level, and " out of the wind," and so firm and 
solid throughout that they will remain in their original 
position ; for timber, if bent or made to wind before it is 
seasoned, will generally retain the same form when dried. 



PLANS OF DIFFERENT BALTIC MODES OfCUTTING DEALS for theENGLISHandFRENCH MARKETS. 
THE SMALLEST TREES ARE CUT FOR DEALS, THE LARGEST FOR LOGS. 



OLD MODE OF CUTTING. 



/ 


■•/ 


'English batten, fx 2S" 


a 


■•'.7 
■■ 1 


ENGLISH DEAL 9x2)fe 


•.1 
- ■ .' .\ 


ENGLISH DEAL. 9x2)1 




••\^ 


ENGLISH BATTEN 7x2)^ 


7 



9x 2>^ -22^^x2 -4-5 

7x 2>t -171^ A 2 "35_ 
80 



All deals ai-e Uahle to dry yx>U if \^^^\^^' t}oe.pLtA ofcWee be leil ul tM 
vlaced^vta^iUcLct with, dump brwhyoTJ^j^smmmmrrrr^ , '1 centre ofcu deal, dry rotatlarkfiW. 



MODE PRACTISED UNTIL THE 
FRENCH MARKET IMPROVED. 



ENGLISH BATTEN>.7x2>i 



ENGLISH ;: DEAL 9x3 



ENGLISH BATTEN 7x2i^ 



9 X 3 - 27 



27 



7x 2>^'-l7)t X 2" 35 
62 



Dry rot first attcu^.s t/u- sapyyood^ 1 -^saninamc^ j SuMwbru. or G(^. deals ar,. m^ 
of a. deal,aful i^^, tJu. pUh. | ^'^ZZ^ ) ^^^ ^ ^^ «^^^^' ^h^ dry rot. 



MODE GENERALLY ADOPTED 
AT THE PRESENT TIME 



■ ./TRENCH 


DEAL 9x 


VA '^ 


/v 


ENGLISH 


DEAL 9 


X 3 


ENGLISH 


DEAL 9 


X 3 




\\\FRENCH 


DEAL 9 X 


'•^T 





W .'p. 



9x3-27x2 -54. 

9 X IJi = I l>i X 2 = 22>^ 
76 '2 



pIc? ncA. c "T^r ^f-^^'^^^- My <J^ rwtpue. sa^ rhcst, hut the Hhrc, t^ur 
-Drc ^ it/ /^^ "^^ f rrLeUay,, ami r^/ubit w.n/ky tea^ture- wtvm. plaiu'd . 

BESTS Wlwll^' free' fr^orrv kr>ou: shrjA4.us,sap}ycod, or cross gj'aw , and well seasoned. 
Vmo^^'^^./fT^'^'''^ -^^''^''^' ^'^^ '^npwood: small knots alUmed 
^\i\m^.AU U(£UJrcr7uxmM<xner beMs" iUuJU secarvdJ' have' hi^^n pudced vut 



DRY ROT IN TIMBER. 65 

Blocks of wood should be put between the " sticks " of 
timber, and each piece directly over the other, so that air 
may freely pass through the whole pile ; for while it is 
necessary to shield timber from strong draughts of wind 
and the direct action of the hot sun, a free circulation of 
air and moderate warmth are equally essential. 

If timber is not used round, it is good to bore out the 
core; as, by so doing, the drying is advanced, and 
splitting prevented, with almost no sacrifice of strength. 
If it is to be squared into logs, it should be done soon 
after some slow drying, and whole squared, if large 
enough, as that removes much of the sap-wood, facilitates 
the drying, and prevents splitting, which is apt to take 
place when it is in the round form, in consequence of the 
sap-wood drying before the heart, from being less dense. 
If it may be quartered, it is well to treat it so after some 
time, as the seasoning is by that means rendered more 
equal. It is well also to turn it now and then, as the 
evaporation is greatest from the upper side. In France, 
the term " bois du brin," means timber the whole size of 
the tree, excepting that which is taken off to render it 
square. 

To prevent timber warping to any serious extent, it 
should be well seasoned before it is cut into scantlings ; and 
the scantlings should be cut some time before they are to 
be used, in order that the seasoning may be as perfect as 
possible ; and if they can be set upright, so much the better, 
as then they will dry more rapidly. The white lowland 
deals of Norway and the white spruce deals of Canada 
have the same disposition to warp and split on drying. 



66 PREVENTION AND CURE OP 

Du Hamel has shown that it is a great advantage to set 
the timber upright, with the lower end raised a little from 
the ground ; but as this cannot always be done, the timber- 
yards should be well drained and kept as dry as possible. 
'* Ancient architects," observes Alberti, "not only prevented 
the access of the scorching rays of the sun and the rude 
blasts of wind, but also covered the surface with cow-dung, 
to prevent the too sudden evaporation from the surface." 
The warping of timber is attributable by some to the 
manner of its growth. Boards cut out of a tree that is 
twisted in its growth will not keep from warping ; boards 
cut from trees that are grown in open situations have 
another fault, in the heart of the tree not running straight 
like forest-grown wood. In a plank cut from a tree of 
this kind in a straight line, the heart will traverse it 
from one end to another. No treatment will prevent it 
from warping or drying hollow on the side farthest from 
the heart. Where the heart is in the centre of a plank, 
and each side has an equal chance of drying, it will not 
warp ; but there will be a shake or crack upon each side, 
denoting the position of the heart. 

Some deals, and particularly the stringy deals, are very 
hygrometric, and never lose the property, however long 
they have been seasoned, of expanding and contracting 
with change of weather. White Petersburgh deals are 
said to have that property, however long they may have 
been kept, so that if used in the panel of a door, the 
wood alternately enters and recedes from the groove into 
which it fits, as the paint will show when that kind of 
deal has been used for a panel. 



DRY ROT IN TIMBER. 67 

The wood of the north side will not warp so much as 
the wood from the south side. The face of the planks 
should be cut in the direction which lay from east to 
west as the tree stood. If this be done, the planks will 
warp much less than if cut in the opposite direction. 
The nature of the tree, the soil upon which it is grown, 
the position of its growth, the period of the year in which 
it is felled, and the length of time between its felling and 
converting, are the principal points to be considered ; a 
thorough knowledge and study of which is the only true 
principle on which we can hope to deal with the warping 
and converting of timber. 

Wood, when it is cut into small pieces, very soon 
acquires its utmost degree of dryness. Dr. Watson, 
Bishop of Llandaff, in the month of March, cut a piece 
from the middle of a large ash tree that had been felled 
about six weeks, and weighed it; its weight was 317 grains. 
In seven days it lost 62 grains, or nearly one-fifth of its 
weight. It was weighed again in August of the same 
year, but had not lost any more of its weight ; hence it 
had become perfectly dry in the short space of seven days. 
He also found that the sap-wood of oak lost more weight 
in drying than the heart-wood, in the proportion of 10 to 7. 

The time that is required to season or dry a piece of 
timber obviously depends upon its magnitude; as a 
general rule, large timbers will not continue good so long 
as small ones, as sufficient time is rarely given for a 
thorough seasoning. The time required to dry a piece of 
timber, all other things being alike, will depend on the 
quantity of surface exposed to the action of the air ; 

F 2 



68 PREVENTION AND CURE OF 

therefore, while the quantity of timber remains the same, 
the larger the surface, the sooner it will dry. Also, if the 
quantity of surface remains the same, the time of drying 
will be proportioned to the quantity of matter; as the 
greater the quantity of matter under the same surface, 
the longer it will be in drying. 

As drying proceeds most rapidly in small pieces, it is 
therefore important to reduce the timber to its proper 
scantlings or size for use; for however dry a piece of 
timber may be, when it is cut to a smaller scantling it 
will shrink and lose weight, being always less dry in 
the centre than at the surface ; and the more rapidly 
the drying has been carried on, the greater will be the 
difference. Nevertheless, in the first stage of seasoning 
it is best that it should proceed slowly ; otherwise, the 
external pores shrink so close as not to permit the full 
evaporation of the internal moisture, and the piece would 
split from unequal shrinking ; and lastly, it should be 
reduced to the proper scantling, as already observed, 
some time before it is to be framed. Various tables have 
been given by writers on timber, the result of algebraical 
calculations, of the times of seasoning and drying for 
different woods of different lengths, breadths, and thick- 
nesses, in the open air ; but as wood even of the same 
description and quality varies so much, this matter is best 
left to those who are well acquainted with timber. It 
may, however, be stated that the time required for drying 
under cover is shorter than in the open air, in the pro- 
portion of 5 to 7. 

The English shipwright considers that three years are 



DRY ROT IN TIMBER. G9 

required to thoroughly season timber. The timbers for 
ships are usually cut out to their shape and dimensions 
for about a year before they are framed together, and they 
are commonly left a year longer in the skeleton shape to 
complete the seasoning, as in that condition they are 
more favourably situate as regards exposure to the air 
than when they are closely covered in with planking. 

It is worthy of mention that all the harder woods 
require increased care in the seasoning, which is often 
badly begun by exposure to the sun or hot winds in their 
native climates : their greater impenetrability to the air 
the more disposes them to crack, and their comparative 
scarcity and expense are also powerful arguments on the 
score of precaution. Oak timber requires to be very care- 
fully seasoned, as it is generally used in buildings for the 
best description of work, and should unseasoned oak be 
used for ^^ panelling," any shrinkage will be fatal to the 
work. Mr. George Marshall, timber merchant (see the 
Builder^ January 20, 1872), with respect to seasoning oak 
timber, observes : " I should select oak trees known to be 
old and hearty, with clean, straight butts, from 15 inches to 
20 inches in diameter. I should then have the bark taken 
off as they stand, and leave them thus till the winter ; the 
sap will then partially dry out, and make the wood a rich 
brown colour. As soon as they are cut down, have them 
sawn up at once into the lengths you require the panell- 
ing, 6 inches or 8 inches wide and 1 inch to 1^ inch 
thick. Be careful to cut all the heart shakes, by having 
one cut through the centre of the log before edging the 
boards to the required width. With regard to the drying 



70 PREVENTION AND CUEE OF 

process, stack the boards in a shed with a good drauglit 
through it, and load them down, with slips between each 
board, to prevent warping. If this be done they will be 
found to dry well and speedily, and they will not require 
to be exposed to the weather." 

Btr. Kobert Phillips, on seasoning oak for panelling, 
states : " If the tree is large enough for the purpose, cut 
it into four, in sections, by drawing a vertical and hori- 
zontal line across the end, meeting in the centre. If too 
small for this, cut it into 4J-inch or 6-inch plank, as 
soon as possible after felling, and then stack on end out in 
the open : do not lay on the ground, but stand it as nearly 
vertical on its end as possible, and keep it wet during the 
first three months. If the weather is dry, well wet it with 
water poured on the top, and allowed to run down. Let 
the ends stand on a piece of quartering, to keep it out of 
the dirt, or it will be stained some distance up. After 
standing thus for some six months, after putting it in a dry 
place for some time, cut it into the scantlings you require, 
always bearing in mind that oak will, after this seasoning, 
shrink at least half an inch to a foot, in width and thick- 
ness. They should then be stacked and stripped, and 
covered with spare boards, and weighted on the top, for at 
least six months — as much more as possible — in a covered 
shed, with plenty of air, occasionally turned over and shifted, 
till they are dry enough to make dust when planed, and not 
turn the shaving black. They will then be fit for use. 

^' I should advise for the panels to be cut feather-edged 
boards, in radial lines from the centre of the tree : it will 
be a waste of material, but will repay in the beauty of the 



DRY TvOT IN TIMBER. 71 

wood, and the way it will stand without w^arping. Slost of 
tlie panels of our old cathedrals were rent {not sawn) in this 
way, and stand admirably. The butt of the tree should 
be taken, the top being used for a rougher purpose." 

Mr. George Marshall and Mr. Kobert Phillips might 
have mentioned that the oak trees should be of the 
Quercus Rohur species, and not the Quercus Sessilijlora. 
They are easily distinguished when growing by the fol- 
lowing peculiarities : The acorn-stalks of the Bohur are 
long ; the acorns grow singly, or seldom two on the same 
footstalk ; the leaves are short. The acorn-stalks of the 
Sessiliflora are short; the acorns grow in clusters of two 
or three, close to the stem of the branch ; the leaves are 
lo7ig. 

WATER SEASONING. 

When there is not time for gradual drying, the best 
method, perhaps, that can be adopted, especially for sappy 
timber, and if strength is not principally required, is 
immediately on felling to immerse it in running water ; 
and after allowing it to remain there about a fortnight, to 
set it in the wind to dry. Some persons prefer this method 
of seasoning timber, as they say it prevents cleaving, and 
strips and seasons better afterwards. This process has 
been adopted with good results by placing the boards end 
on at the head of a mill race for fourteen or twenty days, at 
most, and then setting the boards upright, and subject to 
the action of the sun and wind ; though it is questionable 
whether the sun will not do them more harm than good. 
As they stand, turn them daily, and when perfectly dry — 



72 PREVENTION AND CUBE OF 

which process will take about one month — it is considered 
they will be found to floor better than timber after many- 
years of dry seasoning. The sap-wood of oak is said to be 
improved by this method, being much less subject to be 
worm-eaten ; and providing it is placed in fresh running 
water, Mr. G. A. Eogers, the celebrated wood carver, is of 
opinion that the colour of the oak is improved. The 
more tender woods, such as alder and the like, are 
less subject to the worm when water seasoned. Beech 
is said to be much benefited by immersion. It should be 
remembered that the timber should be altogether under 
water (chained down beneath its surface), as partial 
immersion is very destructive. Du Hamel considers 
"that where strength is required, wood ought not to 
be put in water." Timber should never be kept floating 
in ponds or docks, as in London ; but it should be 
stacked, as at Liverpool and Gloucester. Timber that 
has been lying for months in ponds or docks is sometimes 
cut up, and in six or seven days fixed in a building; 
consequently, the usual result takes place, viz. dry rot. 
After having been swelled by soaking much beyond its 
former bulk, the baulk of timber is put on the saw-pit, 
and cut into scantlings, and framed while in this wet 
state, therefore it cannot be surprising that the dry rot 
soon appears as a natural consequence. 

Amongst wheelwrights the water seasoning is in general 
favour. It is said that the colour of the white woods is 
improved by water seasoning, boiling, or steaming. The 
Venetians place the oak used for gun-carriages in water 
for two years before it is used, and the timber for sea 



DRY ROT IN TIMBER. 73 

service two or three years under water. The Turks do not 
appear to pay any attention to seasoning, for they fell 
their timber at all times of the year without any regard 
to the season, and although they grow very good oak, it 
is used so green and unseasoned that it not only twists, 
but decays rapidly, as anyone may observe in the houses 
at Constantinople and other Turkish towns. 

Timber is rendered more durable by placing it in a 
stream of water, saturated with lime, for eight or ten days, 
and it also makes it less liable to the attack of w^orms ; 
but it, however, becomes hard after being dried, and is 
difficult to be worked ; and therefore the process should 
be applied to timber which has been sawn into scantlings, 
and is ready for use. Mr. William Chapman, in 1812, 
considered that an immersion of timber in hot limewash 
in deep ponds, exposing little surface to the air, merited a 
trial ; but in 1816, from experiments he had made, he was 
of opinion that it had proved injurious to timber. 

Evelyn states that green elm, if plunged for a few days 
in water (especially salt water), obtains an admirable sea- 
soning. According to Society of Arts Trans., 1819, every 
trace of fungus was eradicated from the ship " Eden," by 
its remaining eighteen months under sea water. Salt water 
is considered good for ship timber, but for timber to be 
employed in the construction of dwelling-houses, fresh 
water is better. Pliny notices, as a fact, that certain 
woods on being dried after immersion in the sea acquire 
additional density and durability. M. de Lapparent, 
late Director of the French Navy, considers that timber 
cannot be seasoned in salt water, but in fresh, or at the 



74 PREVENTION AND CURE OF 

most, in brackish water. The condition of the timber 
which, at the port of Eochefort, is kept in ditches filled 
with fresh water is in this respect most favourable ; that 
kept at Toulon, Brest, and Lorient, where the water is 
brackish, is much less so ; but to estimate their relative 
advantages, it would be necessary to test the average 
density of these waters. It is, however, at Cherbourg 
that this natural preparation of timber is the most ineffi- 
cient, as the beds of sand in which the timber is buried, 
near the Pool of Tourlaville, contain but a small quantity 
of water, which, being nearly always stagnant, very quickly 
exhausts itself, and is very prejudicial. 

At the Cologne International Agricultural Exhibition, 
in 1865, three sleepers were exhibited from the Magde- 
burg Leipsiger Railway, from the Salt Work Branch, at 
Stassfurt, laid in 1857. These were moistened by the 
refuse of the salt which was lost from the load and by the 
rain. The jury in their Report stated that these sleepers 
proved nothing, " because every old table on which fish or 
meat has been salted, proves that a constant moistening 
with salt water preserves the wood from decay, but as soon 
as the process of salting is given up, the salted matter is 
immediately given out, and the timber soon decays. In 
this case it would have been important to have known 
that these sleepers, after having been salted, had lain 
anywhere else than in the Salt Work Branch without 
getting fresh salt applied, and then to have seen if they 
would have been as perfect as they are now. They, 
indeed, prove nothing but the fact that if sleepers be 
daily sprinkled with salt they will remain sound, but the 



DRY ROT IN TIMBER. 75 

price paid for this durability might be very considerable." 
As the use of salt as a preservative agent will be con- 
sidered in the next chapter, it will be best to defer the 
consideration of salt-water seasoning until then. 

In India, teak, sal, and blackwood, &c., improve by 
lying in water, or in the soft black mud of an estuary : 
there is one exception, viz. hedde, which deteriorates from 
steeping, and should be carted to its destination. 

Evelyn states that he had found a fortnight's immersion 
in river water suflScient, and this opinion is held by 
Silloway, a North American authority ; but Dr. Porcher, a 
South American writer, recommends a six months' immer- 
sion in water, and a six months' exposure to wind and 
shade. Vitruvius and Alberti consider that timber should 
be left immersed in a running stream thirty days. 

It is considered that the longer wood has remained 
under water, the more rapidly it dries ; for instance, every 
one is aware that the firewood brought out of the river is 
less green and burns better than that brought by waggon 
or boat. 

In 1817, Admiral Count Chateauvieux, a Sardinian 
naval oflScer, observed to Mr. Mc William that it was a 
custom at the Koyal Arsenal, at Genoa, as a preventive 
against the diseases of timber, to steep it about three years 
in fresh water immediately after it is felled. Mr. James 
Dickson, of Gottenburg, timber merchant (member of 
the firm Peter Dickson and Company, London), many 
years engaged in the Swedish timber trade, observed in 
1835, " If square timber lies in the water two or three 
years, it rends at the heart, but I should not say it would. 



76 PREVENTION AND CURE OF 

perhaps, for the first year ; but the exterior part rends 
soon by exposure to the weather." In 1818, the Chevalier 
de Campugano, Secretary of Legation to the Spanish 
Embassy, stated that in Spain, when timber is felled, it 
is generally laid in water for a considerable time. 

The sap in timber, by reason of the matters which it 
holds in solution, is denser than pure water ; moreover, it 
is enclosed in fibres or channels permeable at the ends. 

Supposing' in submerged timber, the surrounding water 
to be flowing, or at least changing, this water will con- 
clude by occupying, if not altogether, at least in a great 
degree, the place of the sap, which will have issued forth, 
carrying with it the fermenting principle with which it is 
charged. The timber, therefore, which has remained 
sufficiently long in the water ought to be much less sus- 
ceptible of fermentation than that seasoned only by the 
atmosphere. Besides, as pure water evaporates much easier 
than that which contains certain principles, this timber 
ought to be seasoned much sooner than the other. 

Of steeping generally, whether in cold or warm water, 
it must be particularly observed that it dissolves the sub- 
stance of the wood, and necessarily renders it lighter ; 
indeed, it is known that notwithstanding wood that is 
carefully submerged remains good for a very long period 
after the water has dissolved a certain soluble part, it is, 
when taken out and dried, liable to be brittle, and unfit 
for any other work but joinery. 



DRY ROT IN TIMBER. 77 

SEASONING BY STEAMING AND BOILING, ETC. 

For the purposes of joinery, steaming and boiling are 
very good methods, as the loss of elasticity and strength 
which they produce, and which are essential in carpentry, 
is compensated by the tendency to shrinkage being re- 
duced; the durability also is said by some to be rather 
improved than otherwise, at least from steaming. If 
steaming be not carried on too quickly it will answer, but 
if it be pushed with too much vigour it is very apt to pro- 
duce a permanent warping and distortion of the material. 
Oak of British growth may be seasoned by this process, 
as without this precaution it requires a long time to 
season. It has been ascertained, that of woods seasoned 
by these methods, those dried soonest that had been 
steamed ; but the drying in either case should be some- 
what gradual, and four hours are generally sufficient for 
the boiling or steaming process. The question of time 
will depend upon circumstances : some persons consider 
that one hour should be allowed for every inch in thick- 
ness. In some dockyards, salt water is used in the boilers, 
in others fresh, from considerations of convenience; and 
the fact is, plank boiled in salt water never gets rid of the 
salts that naturally enter the pores of the wood in boiling ; 
and such being the case, the ship in which this plank is 
used is much more liable to the effects of damp than she 
would have been if the plank had been boiled in fresh 
water. 

Boiling and steaming are likewise employed for soften- 
ing woods, to facilitate the cutting as well as bending of 



78 PREVENTION AND CURE OF 

them. Thus, in Taylor's patent machines for making 
casks, the blocks intended for the staves are cut out of 
white Canada oak to the size of 30 inches by 5 inches 
and smaller. They are well steamed, and then sliced into 
pieces ^ inch or f inch thick, at the rate of 200 in each 
minute, by a process far more rapid and economical than 
sawing ; the instrument being a revolving iron plate of 
12 feet diameter, with two radial knives arranged some- 
what like the irons of an ordinary plane or spokeshave. 

How far steaming or boiling affects the durability of 
timber has not been satisfactorily ascertained ; but it is 
said that the planks of a ship near the bows, which are 
bent by steaming, have never been observed to be affected 
with dry rot. With respect to boiling, Du Hamel's 
opinion is not favourable as to its adding to the durability 
of timber ; for when a piece of dry wood was immersed in 
boiling water, and afterwards dried in a stove, it not only 
lost the water it had imbibed, but also a part of its sub- 
stance ; and when the experiment was repeated with the 
same piece of wood, it lost more of its substance the second 
time than it did the first. Tredgold — no fnean authority 
— considers that "boiled or steamed timber shrinks less, 
and stands better than that which is naturally seasoned." 
Barlow is of opinion that " the seasoning goes on more 
rapidly after the piece is steamed than when boiled." 

At the close of the Crimean and Baltic campaigns the 
port of Cherbourg was almost completely cleared of staves 
sufficiently seasoned for making casks. The engineer at 
the head of the coopering department determined to boil 
in fresh water the newly-cut staves, and compare the time 
of their seasoning with that of other staves cut from the 



DRY ROT IN TIMBER. 79 

same forests, but not prepared ; and the result was that 
after four or five months' exposure to the atmosphere, the 
boiled staves were perfectly fit for working up, while to 
bring the others to the same point fifteen months were 
barely sufficient. 

Steaming is understood to prevent dry rot. No doubt 
boiling and steaming partly remove the ferment spores, 
but maij not destroy the vitality of those remaining. For, 
according to Milne-Edwards, on ' Spontaneous Generation,' 
he has seen tardigrades resist the prolonged action of a 
temperature of 248° Fahr., and has known them to sur- 
vive a temperature of 284° Fahr. That low forms of 
vegetation are fully as tenacious of life cannot be doubted. 

Boiling and steaming also coagulate the albumen at 
140° Fahr. Although coagulated albumen is insoluble in 
water, the water solution is by this heating process sealed 
up in the wood, and the cohesion of the latter is said to be 
diminished. 

The first essays in the art of drying wood artificially 
carry us back to a period now tolerably remote. WoUaston 
and Fourcroy both recommended the drying of wood in 
ovens. Newmann, a German chemist, suggested another 
method, which has since been adopted in a somewhat 
different form, i. e. steaming the wood. Newmann placed 
the wood to be dried in a large wooden chest, taking care 
to leave spaces between the pieces, and then turned on 
the steam from a boiler provided for the purpose. The 
condensed steam, charged with albuminous matter taken 
up from the wood, or rather from its surface, was run off 
from time to time, and the process of the operation was 
judged by the colour of the water. When the latter was 



80 PKEVENTION AND CURE OF 

clear and colourless the chest was opened, and the wood 
withdrawn for use without further preparation. The pro- 
cess would have been useful enough if suioerlieated steam, 
which would have dried the wood by absorbing the 
moisture, could have been used, but the cost of the pro- 
cess would doubtless have been too high to permit of its 
practical application. 

In 1837, M. de Mecquenem devised a method of desic- 
cation, in which the pieces of wood to be dried were placed 
in a closed chamber, and subjected to a current of hot air, 
heated for the purpose by a special apparatus, and driven 
by a blower. The air entered by apertures in the lower 
part of the chambers, and escaped at the top laden with 
the moisture absorbed from the wood. 

In 1839, M. Charpentier obtained a Irevet d'invention 
for a process of drying wood in hermetically -closed 
chambers. The wood was subjected to the action of air 
heated by contact with metal plates covering the flue of 
a coke furnace. This air entered by conduits on the level 
of the floor of the chamber, and escaped at the top through 
apertures leading into the chimney of the furnace. 

In the same year, M. Saint Preuve invented a process 
for forcing steam into pores of the wood, and, by con- 
densation of this steam in the pores, sucking in a pre- 
servative preparation. 

In 1847, MM. Brochard and Watteau's process was 
introduced. It consists simply of filling the cylinder 
with steam, and making a vacuum by forcing in a cold 
solution of salt, &c. 

The plan which has been for some years in use in 



DRY ROT IN TIMBER. 81 

England is the injection, by means of a ventilator, of hot air 
into the drying stove where the wood is placed : by this the 
temperature is gently and gradually raised until it reaches 
boiling heat. But, as wood is one of the worst conductors 
known of caloric, if this plan is applied to large logs, 
the interior fibres still retain their original bulk, while 
those near the surface have a tendency to shrink ; the con- 
sequence of which would be cracks and splits of more or 
less depth. 

Timber may be dried by passing rapid currents of 
heated air through it under pressure. This plan was 
carried out with the timber used for the floorings of the 
Coal Exchange, London. The wood was taken in its 
natural state, and in less than ten days it was thoroughly 
seasoned. In some cases, from 10 to 48 per cent, of 
moisture was taken out of the wood, and although the 
floorings have now been down a great many years, it is 
stated that very little shrinkage has been found, except in 
the case of a few pieces which were put down in the latter 
portion of the work, and which had not been submitted to 
the seasoning process. 

The process of desiccation, patented by Messrs. Davison 
and Symington, in 1844, is of great practical value in 
reducing the time requisite for seasoning timber. It is 
peculiarly applicable to the seasoning of flooring boards 
and of the wood used in joiners' work. Care must be 
exercised when removing the timber from the stove to the 
building in which it is to be used, that it be not exposed 
to the wet, nor even to a damp atmosphere for any 
lengthened period. The advantage of this process over 



82 PREVENTION AND CUKE OF 

the ordinary stoving consists in the temperature never 
being so high as to scorch the wood, by which the 
strength of the fibres would be injured ; and in the facility 
for removing the vapour as fast as it is expelled from the 
wood, in consequence of the air being propelled through 
the stove at any required velocity and temperature. As 
compared with furnace and steam-stoving ordinarily 
employed to desiccate woods, the great superiority of this 
process is established by its seasoning the wood quite as 
rapidly, but much more thoroughly ; and instend of wood 
being rendered brittle, as it is to some extent by stoving, 
this mode does not reduce the strength and tenacity of 
the wood. The principle of the invention is propelled 
currents of heated air ; but the heat has to be regulated 
according to the texture of the various woods. Honduras 
mahogany might be exposed to a heat of 300°, and the 
whole of the moisture can be taken out in three days. 
Timber 9 inches square is considered by Mr. Davison a 
proper size for his invention. This process is described as 
^' A method or methods of drying, seasoning, and harden- 
ing wood, and other articles, parts of which are also 
applicable to the desiccation of vegetable substances 
generally." The first or principal part of the invention 
consists in drying, seasoning, and hardening wood and 
other articles — among which other articles are included 
generally all things made of wood, or chiefly of wood — by 
means, as has been stated, of rapid currents of heated 
air. The manner in which these currents of heated air 
are produced, is by an apparatus consisting of a furnace 
and a series of pipes withinside of a core of brickwork. 



DRY ROT IN TIMBER. 83 

On eacli side of the furnace, on a level with the fire-bars, 
is a horizontal tube ; communicating and springing from 
these tubes are a series of eighteen tubes placed vertically 
and parallel to each other over the furnace. The outer 
end of one of the horizontal tubes communicates with a 
fan or other impelling apparatus for driving a constant 
stream of atmospheric air through the tubes. As tlie air 
passes through the tubes it becomes heated at a high 
temperature, and rushes out at the farther end of the 
other horizontal tube, and is thus conveyed to the place 
where it is applied. The materials to be subjected to the 
heated currents, such as logs, deals, &c., by outward appli- 
cation, must be placed in closed chambers, galleries, 
vaults, or flues, which are to be of any suitable form or 
magnitude ; but it is recommended that they should be 
made of fire-brick, and have double doors or shutters for 
introducino: or removino; the wood. Honourable Mention 
was made of Messrs. Davison and Symington's process of 
desiccation, by the jury. Class IV., Exhibition of 1851, 
England. 

Some amusing instances are related of the efficiency of 
Davison and Symington's process. Thus, a violin had 
been in the owner's possession for upwards of sixteen 
years ; how old it was when he first had it is not known. 
Upon being exposed to this process it lost, in eight hours, 
no less than five-sixths (nearly five and two-thirds) per 
cent, of its own weight. This there is every reason to 
believe was owing to the blocks glued inside, for the 
purpose of holding the more slender parts together. A 
violin maker of high reputation, having an order to make 

G 2 



84 PREVENTION AND CURE OF 

an instrument for one of the first violinists of the day, 
was requested to have the wood seasoned by this process ; 
only three days were allowed for the experiment, in which 
the wood was seasoned and sent home. The two heaviest 
pieces were reduced in weight 2^ lbs. It is ascertained 
that, by this means of drying, the effect of age has been 
given to the instrument made from the- above wood, and 
it was, in 1848, first fiddle in the orchestra of Her 
Majesty's Theatre, London. The wood had been in the 
possession of its owners for eight years, and it was sent 
from Switzerland, in the first instance, as dry wood. 

In proof of the value of this invention for the manufac- 
ture and cleansing of brewers' casks, it was stated, in 1848, 
that since its adoption at Trueman's brewery, Spitalfields, 
a saving of 300 tons of coals has been effected annually. 

Flues or chambers for the heated air may be con- 
structed in parallel lines, either in the floors or upright 
walls of a building, having narrow openings through 
which the heated air may issue in thin streams, and 
spread itself over the surface of the wood. If the 
openings are in the floor, the wood will require to be 
placed in an upright position; but if admitted in a 
horizontal direction, standards and skeleton shelves will 
be necessary to lay it upon. The great object, in all cases, 
is to bring the heated air as speedily as possible into con- 
tact with the wood, and to allow it, after it has done its 
office, to pass away as speedily. 

Furnaces and apparatus for the production of rapid 
currents of heated air may be erected to prepare any 
quantity of timber or articles of wood at one time, but 



DRY EOT IN TIMBER. 85 

care should be taken that whatever the size of the outlet 
may be from the series of pipes or vessels by which the 
heat is generated, an outlet of at least equal dimensions is 
left for the free exit of the air and the vapours thrown off. 
It should also be observed, in constructing the open space 
in the floor or upright w alls for the stream of heated air to 
pass towards the timber, that the superficial area of the 
whole of them combined does not exceed the dimensions 
of the principal outlet of the pipes at the extremity of 
the furnace, so that a free current of heated air may be 
allowed to pass uniformly throughout the chambers con- 
taining the wood to be prepared. The temperature proper 
to be given to the air, and velocity to the current in each 
case, will depend on the size, density, and maturity of the 
wood to be acted upon. The inventors found by their 
experiments that wood generally may be advantageously 
subjected to currents of air raised to a temperature of 400"" 
Fahr., when the currents are impelled at the rate of 100 
feet per second. But when the wood is in a green state, it 
is better to commence at a lower temperature, say from 
ISO"" to 200°, and gradually raise it to the high degree 
before stated, as the desiccation proceeds, an object which 
may, in some cases, be facilitated by carrying a cold-air 
drain from the fanner or other propelling apparatus, and 
attaching a damper to it, so that any quantity of cold air 
required to reduce the temperature of the hot current 
may, from time to time, be admitted. When, again, the 
wood is in the log or unconverted state, it should be bored 
or augured out in the centre, and the current of hot air 
caused to traverse it as well interiorly as exteriorly, 



86 PREVENTION AND CURE OF 

whereby much time will be saved in the process of 
desiccation, and a more uniform result obtained. 

Woods treated in this manner, and with the above 
modifications when requisite, part rapidly with their 
ftatural sap and any other aqueous matter which they 
may contain, and the fibres are brought closer together. 

With respect to the time required to season the wood 
upon this plan, much must depend upon the original state 
of dryness it may be in, as well as the quality and 
temperature of the heated air forced into contact with it. 
It may suffice to remark that the wood may safely remain 
thus exposed till any escape of moisture ceases to be 
perceptible. This may be readily known, either by 
applying a mirror or any polished surface to the outlet, or 
by calculating the quantity of moisture removed from the 
wood, which will be found to range between J and yVth of 
its whole weight. For the purpose of ascertaining more 
correctly the amount of moisture removed from time to 
time, when the wood is placed in seasoning chambers as 
already described, an opening should be constructed in 
the chamber, in any convenient position, through which a 
specimen of the wood may be withdrawn and weighed. 

Between 1848 and 1853, Mr. Bethell, who had paid 
much attention to the subject, obtained several patents, 
both in England and France, for stoves for drying wood. 
In his English patent of 1848, and the subsequent French 
one of 1853, we find a description of a peculiar kind of 
stove, on the following plan : 

It consisted of a rectangular chamber formed of three 
walls and vaulted over, the whole in brickwork, with a 



DRY HOT IN TIMBER. 87 

certain thickness of slag in the centre, to prevent loss of 
heat. One extremity of the chamber was open to admit 
of the introduction of the wood by means of a truck 
running upon longitudinal iron rails. The opening w^as 
closed with a double door when the chamber was full. On 
the exterior of the opposite end of the chamber was a 
furnace to burn coal, coke, wood, or tar, according as it 
was desired to dry the wood simply, or, in the words of 
the inventor, to smohe it, i. e., to impregnate it with the 
antiseptic gaseous matters evolved in the imperfect com- 
bustion of certain tarry substances. The heated air or 
smoke entered through a flue running along the floor and 
branching at the end, and it escaped, or was pumped out, 
at the top of the vaults. Bethell considered that the 
interior of the chamber should be kept at a temperature 
of 110^ Fahr., and that the duration of the process should 
be regulated by the condition of the wood. His experi- 
ments showed that this time varied from eight to twelve 
hours, the rapidity being attained at the cost of a relatively 
large expenditure of fuel. In point of fact, the draught 
was too great to permit of the utilization of the full 
amount of heat contained in the gaseous matter, w^hich 
escaped at a temperature very little below that at w^hich 
it entered. The heat produced by the fuel was badly 
utilized, and it is open to question whether, under any 
circumstances, large pieces of wood, such as sleepers, 
could be dried in so short a time as eight or twelve hours. 
The drying could only be effected by the use of a very 
high degree of temperature, tending to split the wood and 
weaken its strength. This view was confirmed by the 



88 PREVENTION AND CURE OF 

results obtained in a long series of experiments made, in 
1852-3, by an English manufacturing company, known as 
the Desiccating Company. A low temperature, and long 
continuance of the drying process, appear to be the con- 
ditions essential to the success of artificial desiccation, 
particularly with wood intended for cabinet-making, 
turning, joinery, ornamental work, &c., in which it is 
desirable, as far as possible, to prevent splitting, warping, 
and other changes of structure in the material. These 
results, it would seem, were not secured by the arrange- 
ments above described. 

Some years since, a stove was constructed for Messrs. S. 
and J. Holme, very extensive builders at Liverpool, for 
the purpose of drying timber for floors, and other fittings 
of houses, &c., by the application of Messrs. Price and 
Manby's patent warming apparatus ; the want of seasoned 
timber, with the great number of men they employed? 
being a serious inconvenience and loss. In their large 
undertakings Messrs. Holme found a difiSculty in keeping 
a stock of dry timber. The dimensions of the stove in 
which the timber was to be dried was 43 feet long, 11 feet 
wide, and 17 feet 6 inches high, and the cost of tlie appa- 
ratus was about 150Z. It was calculated to hold about 
30,000 superficial feet of 1-inch boards, which, upon the 
steam-pipe system, occupied full three weeks in drying. 
This apparatus of Messrs. Price and Manby, with rather 
less fuel, was considered to thoroughly dry each stove-full 
in ten days, thus saving a consumption of ten days' fuel, 
independent of the advantages of expediting business. 
The average temperature was 104°, and as the continuous 



DRY ROT IN TIMBER. 89 

stream of pure air passing between the metallic plates 
was divested of its moisture, it carried off the dampness 
of the timber in an imperceptible manner. An experi- 
ment was tried, by having a flooring batten, 7 inches by 
1^ inch, cut from a piece of timber which had been 
floated, and was as full of water as it could be, placed in 
the stove; and when the temperature w^as 102°, it re- 
mained there five days, and when sawn down into | inch 
thick, and planed, it was found to be perfectly dry 
throughout. The heat was so gentle, and the evaporation 
so equal, that the timber was never rent, as when exposed 
to the air and a hot sun : in short, Messrs. Holme con- 
sidered it one of the most perfect timber stoves that had 
been made. 

It may be remarked wdth respect to desiccation, that 
the timber to be artificially dried is generally exposed to 
a great heat for a short time, rather than to a moderate 
heat for a lengthened one ; and the air, saturated with the 
vapour thus produced, is generally very imperfectly 
removed. Wood so treated is almost sure to split, from 
the unequal contraction to which it is exposed ; and the 
pores are also very liable to reopen on the wood being 
withdrawn from the stove, because there is no gradual 
and permanent change in their mechanical structure. It 
is only within the last few years past that the artificial 
desiccation of wood, before its impregnation with an anti- 
septic preparation in closed vessels, has been frequently 
adopted in practice. 

We cannot give a better termination to the few remarks 
we have made about ''steaming and boiling timber," 



90 PREVENTION AND CURE OF 

than by quoting the opinion of the late Sir Charles 
Barry, E.x\., architect to the new Houses of Parliament, 
which we propose doing in the following manner : 

" York Eoad, La3ibeth, 
Sir, Nov. 30, 1844. 

In reply to your application, we beg to acquaint 
you that we are willing to undertake the ordinary works 
required in the finishings of the new Palace of West- 
minster .... The wainscot to be used in the joiner's 
work is assumed to be from the best Crown Kiga wains- 
cot in the logs, and from pipe-staves of the best quality, 
in equal proportions, to be prej^ared for use by steaming, 

or otherwise .... 

Grissell & Peto." 
Charles Barry, Esq. 

Sir Charles Barry recommended this tender to the 
Treasury for acceptance; but we fancy that he was 
doubtful about the eflScacy of steaming, as we think will 
appear from the following extract from an "Agreement 
between Sir Charles Barry and Messrs. Grissell and Peto, 
builders : 

"First That the wainscot is assumed to be from the 
log and pipe-staves in equal quantities ; the prime cost of 
which, in inch boards, seasoned hy steam, or other artificial 
means, so as to be fit for use, is calculated at 6^d, per foot 
superficial. 

" Secondly. That if it should he found necessary to make 
use of thoroughly dry icainscot hoards for the whole or any 
portion of the joiner's work, seasoned by natural means 
(viz. exposure to the atmosphere), the prime cost of such 



DRY ROT IN TIMBER. 91 

boards, with the addition of a profit of 7i per cent., is to 
be allowed for them, over and above the price of (i^d. per 
foot superficial, the prime cost of wainscot boards provided 
for in the contract, as above stated." (Italics are our own.) 

SEASONING BY SMOKE DRYING. 

Smoke drying in an open chamber, or the burning of 
furze, fern, shavings, or straw under the wood, is said to 
give it hardness and durability; and, by rendering it 
bitter, destroys and prevents worms. It also destroys the 
germ of any fungus which may have commenced. It is 
an old and well-founded observation that smoke drying 
contributes much to the hardness and durability of woods. 
Virgil appears to have been aware of its utility, when he 
wrote the passage which is thus translated by Dryden : 

" Of beech, the plough-tail, and the bending yoke, 
Or softer linden, hardened in the smoke." — Georgics, i., 225. 

Beckman, in his ^ History of Inventions,' quotes a pas- 
sage from Hesiod to the same effect ; and adds, '' as the 
houses of the ancients were so smoky, it may be easily 
comprehended how, by means of smoke, they could dry 
and harden pieces of timber." In this manner were pre- 
pared the pieces of wood destined for ploughs, waggons, 
and the rudders of vessels : 

" These long suspend, where smoke their strengtli explores, 
And seasons into use, and binds their pores." — Virgil. 

The late Brigadier-General Sir Samuel Bentham 
bestowed much time and attention in endeavouring to 
ascertain the quickest and best means of drying oak. In 



92 PREVENTION AND CURE OF 

his letter to the Navy Board, 6th March, 1812, he says: 
^' By exposing block shells to the smoke of burning wood, 
they become in the course of two or three days well sea- 
soned in every respect, hard, bright coloured, and, as it 
were, polished. But it was found in a very short time that 
the acid with which the shells were thus impregnated 
very rapidly corroded the iron pins which passed through 
them. 

" In Eussia many small articles, such as parts of wheels, 
wheel carriages, and sledges, are prepared in this manner ; 
so are wheels, at least in some parts of America ; and 
sabots and other small articles in France." 

In speaking of artificial heat, he says, in the same 
letter : 

" From all the opportunities I have had of examining 
the state of timber so prepared by artificial heat, the due 
seasoning without cracking has appeared to depend on 
the ventilation happening to be constant^ but very slow, 
joined to such a due regulation of the heat as that the 
interior of the timber should dry, and keep pace in its 
contraction with the outer circles." 

Mr. T. W. Silloway, in ' American Carpentry,' remarks : 
'^If timber be dried by heat, the outside will become 
hardened, and the pores closed, so that moisture, instead 
of passing out, will be retained within." 

Bowden remarks, "that the timbers of a small ship 
underwent the process of charring, either by suspending 
them over a fire of chips, or by burning the exterior with 
red-hot irons, so as to char the external surface. Air 
trunks were also formed between the timbers, for the pur- 



DRY TxOT IN TIMBER. 93 

pose of evaporating moisture. The state of this vessel 
was examined five years after she was launched, and it 
appeared that, although the timbers had been very strongly 
charred, fungi had grown to a considerable extent on both 
sides abaft the fore channels, and that the plank near the 
magazine was completely decayed." The power of vegeta- 
tion broke through the incrusted harrier against external 
affection. 

A method is in operation at Tourlaville, near Cher- 
bourg, for which the inventor, M. Guibert, has taken out 
a patent, and it is said to give at once more expeditious 
and sure results than those obtained from the use of dry 
and hot air. It consists in filling the drying-stove with 
smoke, produced by the distillation of certain combustible 
matters, such as saw-dust, waste tan, and smiths' coals, &c. 
By means of a ventilator, ingeniously arranged, a rotatory 
movement round the logs laid to season is given to the 
smoke, so as to obtain an average uniform temperature in 
every part. By this plan, as the distillation of combus- 
tibles is always attended with a considerable discharge of 
steam, all cracks and splits are said to be prevented. 

There is much force in Sir Samuel Bentham's observa- 
tions respecting the drying of timber by artificial heat : 
it is certainly not well to attempt to dry it too quickly, for 
if it be subjected to great heat, a large portion of the 
carbon will pass ofi", and thereby weaken the timber. 
Timber too suddenly dried cracks badly, and is thus 
materially injured : planks of larch or beech are liable to 
warp and twist if their drying is hastened. 



94 PREVENTION AND CURE OF 

STOVE DRYING. 

Ill some of the large manufactories for cabinet work, 
the premises are heated by steam pipes, in which case 
they have a close stove in every workshop heated many 
degrees beyond the general temperature, for giving the 
final seasoning to the wood ; for heating the cauls ; and 
for warming the glue, which is then done by opening a 
small steam pipe into the outer vessel of the glue-pot. 
The arrangement is extremely clean, safe from fire, and 
the degree of heat is very much under control. 

In some manufactories, the wood is placed for a few 
days before it is worked up in a drying-room heated by 
means of stoves, steam or hot water, to several degrees 
beyond the temperature to which the finished work is 
likely to be subjected. Such rooms are frequently made 
as air-tight as possible, which appears to be a mistake,* 
as the wood is then surrounded by a warm but stagnant 
atmosphere, which retains whatever moisture it may have 
evaporated from the wood. 

Fire-stoves for drying the timber were placed in the 
magazine, bread-room, and other parts of the ^Eoyal 
Charlotte ' ship ; and the evil of this practice was soon 
shown, for the vessel became dry rotten in kvelve months,^ 

Wood sometimes undergoes a baking process for 
veneering. Fourcroy has recommended baking timber 
in an oven, and he has asserted that it would render 
timber more durable; ''but," says Boyden, "it should 
be subjected to a very strong heat, lest in endeavouring 

* See white faces of workmen. 

t See London newspapers, July, 1812. 



DRY ROT IN TIMBER. 95 

to prevent vegetation, we should give it birth." Captain 
Shaw* observes: "Any artificial heating which burns the 
air is most injurious to wood and all combustible mate- 
rials, and renders them much more inflammable than 
they would be if only exposed to the temperature of the 
atmosphere." 

SEASONING BY SCORCHING AND CHARRING. 

Scorching and charring are good for preventing and 
destroying infection in timber, but have to be done 
slowly, and only to timber that is already thoroughly 
seasoned ; otherwise, by incrusting the surface, the evapo- 
ration of any internal moisture is intercepted, and decay 
in the heart soon ensues ; if done hastily, cracks are also 
caused on the surface, and which, receiving from the wood 
a moisture for which there is not a sufiBcient means of 
evaporation, renders it soon liable to decay. Charring 
has little or no control over internal corruption, though it 
is a good preventive against external infection : it in- 
creases the durability of dry, but promotes the decay of 
wet timber. Farmers very often resort to this method 
for the preservation of their fence-posts ; the charring 
should extend a little above their contact with the 
ground. Unless they discriminate between green and 
unseasoned timber, these operations will prove injurious 
instead of beneficial. 

We have already quoted Sir Charles Barry in favour of 
steaming wood ; we now intend giving the opinion of a 
former pupil of his with regard to charring it. Mr. George 

* * Fire Surveys,' p. 58. 



96 PREVENTION AND CURE OF 

Vulliamy, architect to the Metropolitan Board of Works, 
in a specification for oak fencing which was fixed round 
the boundaries of Finsbury Park, London, in 1867, writes 
as follows : — " Dig out the ground for the upright standards 
where shall be directed, and fill in and ram round same 
with dry burnt earth, stones, and rubbish (the burnt clay 
will be provided) ; enclose the boundaries of Park, as 
shall be directed, with dry and well-seasoned heart of 
English oak, wrought upright standards, 6 inches by 
5 inches, and 8 feet 6 inches total length, with cut and 
splayed tops, holes drilled for oak pins, and mortised for 
horizontal rails, as shown on detailed drawings ; to stand 
5 feet 3 inches out of ground, and the ends in ground to 
he well charred he/ore fixing^ (The italics are our own.) 

Our ancestors used charcoal and charred wood, on 
account of their durability, for landmarks in the ground 
between estates. The incorruptibility of charcoal is well 
known. Amongst other advantages, rats will not touch 
it; neither will the white ants nor cockroaches, so 
common in the Indies, commit their depredations where 
charring has been employed. 

The 'Kevue Horticole' states that it has been proved by 
recent experiments, that the best mode of prolonging the 
duration of wood is to char it, and then paint it over with 
three or four coats of pitch. Many of the sleepers now laid 
down on the Belgian railways are charred, the engineers 
preferring this process to any other. 

The superficial carbonization, or charring of wood, as a 
preservative means, has long been practised. The Vene- 
tians have used charring for timber for a loDg period, 



DRY ROT IN TIMBER. 97 

particularly for piles. In France, M. de Lapparent 
recently proposed to apply it to the timber used in the 
French Navy. Some experiments, which were undertaken 
with a view to determine its practicability, terminated 
satisfactorily; and the Minister of Marine ordered the 
process to be introduced into the Imperial dockyards. 

M. de Lapparent makes use of a gas blowpipe, the 
flame from which is allowed to play upon every part of 
the piece of timber in succession. By this means the 
degree of torrefaction may be regulated at will. The 
method is applicable to woodwork of all kinds ; and the 
charring, it is said, does not destroy the sharpness of 
any mouldings with which the wood may be orna- 
mented. 

In the 'Journal des Savants,' Feb. 15, 1666, appears 
the following: "The Portugals scorch their ships, in- 
somuch that in the quick works there is a coaly crust of 
about an inch thick ; but this is dangerous, it happening, 
not seldom, that the whole vessel is burnt." It is no wonder 
that the Portuguese ships should frequently fire in the 
operation, as their plank was charred an inch deep. A 
mere charring, if done properly, after the timbers had 
been thoroughly seasoned by air, would have been 
sufficient. 

Charring seasoned wood is known to be a most effectual 
mode of preservation against rot in timber : thus do piles, 
when charred, last for ages in water or moist soil. Charred 
wood has been dug up, which must have lain in the ground 
for 1500 years, and was then found perfectly sound. After 
the Temple of Diana, at Ephesus, was destroyed, it was 

H 



98 PREVENTION AND CURE OF 

found to have been built on charred piles ; and at Hercu- 
laneum, after 2000 years, the charred wood was found to 
be whole and undiminished. But we find Sir Christopher 
Wren did not approve of charred piles, except in a soil 
where they would be constantly wet. So, in order to 
attain a firmer foundation for St. Paul's Cathedral, he had 
the ground excavated to an immense depth before a stone 
of the building was laid. 

From time immemorial it has been the practice, parti- 
cularly in France, to burn the ends of the poles driven 
into the ground to preserve them from decay. According 
to the remark of the celebrated Carlomb, we should 
always take into serious consideration old and well-known 
customs; but in this instance it is easy to admit the 
preserving efi'ect of carbonization. Mr. James Randall,^ 
Architect, states that he " oxidated several pieces of wood 
with nitric acid, and with fire," and these processes were 
attended with success. Nearly the last sentence in his 
work is, '* oxidation only can be relied on, in all cases, as 
an effectual cure." 

In charring, the surface of the timber is subjected to 
a considerable heat, the primary effect of which is to 
exhaust the sap of the epidermis, and to dry up the 
fermenting principles. Here this is done by long exposure 
to the air; and, in the second place, below the outside 
layer completely carbonized, a scorched surface is found, 
that is to say, partly distilled and impregnated with the 
products of that distillation, which is creosoted; the 
antiseptic properties of which are well known. 

When Mr. Binmer was examined before the Commis- 

* ' Directions to Cure the Dry Rot.' 1807. 



DRY ROT IN TIMBER. 99 

sioners of Woods, Forests, &c., in 1792, he stated '• that 
all steamed plank should be afterwards dried and hurnt to 
extract the moisture." 

To a spontaneous carbonization must be attributed also 
the unchangeableness of that timber entirely black, wliich 
is met with everywhere in digging up the ground, where 
it has laid buried for ages. In the neighbourhood of 
St. Malo, France, these specimens are very common, and 
there most of the espaliers and vine props are made of 
wood, black as ebony, and famous for its durability. They 
have been cut from the trees of an old forest, submerged 
in the eighth century by an inroad of the sea, which for- 
merly crossed a Eoman road, leading from Brittany to 
Cotentin. 

Not long after the beginning of the eighteenth centur}-, 
the method of heating or charring timber, before it 
was w^orked up, and also that of stoving — tliat is, of 
heating in kilns with sand — were practised in the Eoyal 
dockyards. The ' Eoyal William,' one of the most 
remarkable instances of durability that the British Navy 
has supplied, was built either wholly or in part of timber 
that had been charred. It was launched in 1719; never 
repaired until 1757; and then, when surveyed afloat, in 
1785, it appeared that the thick stuff and plank had been 
hurnt instead of being kilned; and that the ends of the 
beams, the faying parts of the breast-hooks, crutches, 
resters, knees, &c., had been gouged in a manner then 
practised, which was called snail- creeinng ; by means of 
which the air was conveyed to the different parts of the 
ship.* 

* See Report of the Officers of Portsmouth Yard, 1702. 

H 2 



100 PREVENTION AND CURE OF 

The reason this method has not been persevered in, but 
nearly abandoned, is owing to many causes : the difficulty 
and danger of the means adopted for charring, when 
either straw^, fern, or shavings are made use of; the 
serious objection of burning the timber too deeply ; or the 
encumbrance of the apparatus, and the length of time 
occupied, if sand-kilns sufficiently heated are used ; and, 
finally, to indifference, or that system of routine, against 
which the wisest plans often contend in vain. 

In house - building, the charring process should be 
applied to the beams and joists embedded in the walls, or 
surrounded with plaster; to the joists of stables, wash- 
houses, &c., which, although exposed to the free air, are 
constantly surrounded by a warm and moist atmosphere, 
an active cause of fermentation ; to the wainscotting of 
ground floors ; to the flooring beneath parquet work ; to 
the joints of tongues and rabbets; for carbonization by 
means of gas still leaves to the wood^ for working pur- 
poses, all the sharpness of its edges. Charring is particu- 
larly useful in the junction of all broad surfaces, and more*' 
essentially in those which are cut either transverse or 
oblique to the grain of the wood, as the sap vessels are 
then exposed to the absorption of moisture. The butts of 
timbers are peculiarly liable to rot, because of affording a 
lodgment for moisture without a free passage for air. No 
seasoned timber should have its tubular parts exposed, 
nor should any timber have the saw marks upon it, 
because the torn filaments absorb and retain moisture. 
Allusion has already been made to the process adopted, 
near Cherbourg, for preventing the decay of timber by 
means of gas. 



DRY ROT IN TIMBER. 101 

By carbonization, a practical and economical means is 
afforded to railway companies of preserving, almost for 
ever, the sleepers, and particularly oak, which cannot be 
impregnated easily by the injection of mineral salts. Let 
us suppose, for instance, that after, say ten or fifteen years, 
the sleepers on a line are taken up for the length of a 
mile, and replaced by new ones ; the old, when rasped and 
burnt again, will serve for the replacing the following 
mile, and so on, one mile after the other. It might be 
equally serviceable to apply the same process to injected 
beech, for the reason that it is almost impossible to make 
the preserving liquid penetrate thoroughly the mass of the 
timber. 

SEASONING BY EXTRACTION OF SAP. 

Mr. John Stephen Langton's method of seasoning by 
extraction of the sap was patented in 1825, but is now 
almost wholly discontinued. It consists in letting the 
timber into vertical iron cylinders, standing in a cistern 
of water, closing the cylinders at top; and the water 
being heated, and steam used to produce a partial vacuum, 
the sap relieved from the atmospheric pressure oozes from 
the wood, and being converted into vapour, passes off 
through a pipe provided for the purpose. The time 
required is about ten weeks, and the cost is about ten 
shillings per load ; but the sap is wholly extracted, and 
the timber is said to be fit and ready for any purpose ; 
the diminution of weight is, with a little more shrink- 
age, similar to that in seasoning by the common natural 
process.* 

* See Tredgold*s Report on this process, May 2, 1828, 



102 PREVENTION AND CURE OF 

Mr. Barlow's patent provided for exhausting the air 
from one end of the log while one or more atmospheres 
j^ress upon the other end. This artificial aerial circulation 
through the wood is prolonged at pleasure. However 
excellent in theory, this process is not practicable. 

In October, 1844, M. Tissier proposed to place wood 
in a (ilose vessel, and subject it to a current of hot dry 
air ; and in 1847, Mr. Miller proposed to inject hot air 
through beams of wood to drive out the sap. 

In 1851, M. Meyer d'Uslaw proposed to first dilate the 
pores of the wood with steam, and then place it in a 
hermetically closed chamber, and make a vacuum there. 

The following system of preparing timber for the Navy 
was, not many years since, adopted in South Eussia. A 
full account of the practice will be found in Oliphant's 
'Kussian Shores of the Black Sea,' 1853. The only 
name we can give it is 

" ' SEASONING ' BY BRIBES." 

A certain quantity of well-seasoned oak being required, 
Government issues tenders for the supply of the requisite 
amount. A number of contractors submit their tenders 
to a board appointed for the purpose of receiving them, who 
are regulated in the choice of a contractor not by the 
amount of his tender, but of his bribe. The fortunate 
individual selected immediately sub-contracts upon a 
somewhat similar principle. Arranging to be supplied 
with the timber for half the amount of his tender, the 
sub-contractor carries on the game, and perhaps the eighth 
link in this contracting chain is the man who, for an 



DRY ROT IN TIMBER. 103 

absurdly low figure, undertakes to produce the seasoned 
wood. 

His agents in the central provinces accordingly float 
a quantity of green pines and firs down the Dnieper and 
Bog to Nicholaeff, which are duly handed np to the head 
contractor, each man pocketing the difference between his 
contract and that of his neighbour. When the wood is 
produced before the board appointed to inspect it, another 
bribe seasons it ; and the Government, after paying the 
price of well-seasoned oak, is surprised that the 120-gun 
ship, which it has been built of it, is unfit for service in 
five years. 

*' Mark but my faU, and that that niin'd me, 
Corruption." — Shakspeake. 

A few words can only be given to a most important 
matter, viz., the second seasoning, which many woods 
require. If floor-boards are only laid down at first on the 
joists of a building, and at the expiration of one year 
wedged tight and nailed down, those unsightly openings 
caused by shrinkage, which form a harbour for dirt and 
vermin, will be avoided, as the wood will have had an 
opportunity of shrinking. Doors, sashes, architraves in 
long lengths, will also be better if made up some time 
before they are required for use. Many Indian woods 
require a second seasoning — kara mardd, for instance, a 
favourite wood with Indian railway engineers. Even sal 
and teak are not exempt. Teak shrinks sideways least of 
all woods. In the ' Tortoise,' store ship, when fifty years 
old, no openings were found to exist between the boards ; 
yet Colonel Lloyd says he found the teak timbers used by 



104 PREVENTION AND CURE OF 

him in constructing a large room in the Mauritius to have 
shrunk f of an inch in 38 feet Thus a space of | of an 
inch must have been left at each end of the beam, where 
moisture could lodge and fungi exist, obtaining their 
nourishment from the wood. If unseasoned teak is used 
for ships, dry rot will in time find a place. It may be 
said that teak is a very hard wood, and very durable ; 
yet " the mills of the gods," says an ancient philosopher, 
'* grind slow, very slow, but they grind to powder;" and 
so do the fungi mills. 



DRY EOT IN TIMBER, 105 



CHAPTER Y. 

ON SEASONING TIMBER BY PATENT PROCESSES, ETC. 

Long years of practical experience has shown that timber, 
however prone to dry or wet rot, may be preserved from 
both by the use of certain metallic solutions, or other 
suitable protective matters. 

All the various processes may be said somewhat to 
reduce the transverse strength of the timber when dry, 
and the metallic salts are affected at the iron bolts or 
fastenings. The natural juices of some woods do this; 
and bolts which have united beams of elm and pitch pine 
will often corrode entirely away at the junction. 

The processes adopted for resisting the chemical changes 
in the tissues of the wood are all founded on the principle 
that it is essential to inject some material which shall 
at once precipitate the coaguable portion of the albumen 
retained in the tissues of the wood in a permanent in- 
soluble form, so that it will not hereafter be susceptible 
of putrefactive decomposition. For this purpose, many 
substances, many solutions, have been employed with 
variable success, but materials have been sometimes in- 
troduced for this purpose which produced an effect just 
the opposite to what was anticipated. 

Experience has shown that timber is permeable, at least 
by aqueous solutions, only so long as the sap channels are 
free from incrustation. 



106 PREVENTION AND CURE OP 

Such in general is the case with beech, elm, poplar, and 
hornbeam, the capillary tubes of which are always open, 
or, at least, close very slowly. At the same time it may 
be said that there must remain ever in these species some 
parts impervious to injection, w^hilst it is almost impossible 
but that a certain portion of the fibres will be more or less 
incrusted. The sap woods, on the other hand, of every 
species appear quite pervious. 

Very little is known of any preservative process adopted 
in ancient times. Pliny observes that the ancients used 
garlic boiled in vinegar with considerable success, espe- 
cially with reference to preserving timber from worms : 
he also states that the oil of cedar will protect any timber 
anointed with it from worm and rottenness. Oil of cedar 
was used by the ancient Egyptians for preserving their 
mummies. Tar and linseed oil were also recommended by 
him. The image of the goddess Diana, at Ephesus, was 
saturated with olive and cedar oils; also the image of 
Jupiter, at Kome ; and the statues of Minerva and Bacchus 
were impregnated with oil of spikenard. 

The idea of preserving wood by the action of oil is 
therefore by no means new; but it is somewhat curious 
that the earliest modern processes should also be by 
means of oil. The oils most proper to be used are Unseed, 
rapeseed, or almost any of the vegetable fixed oils. Oak 
wood, rendered entirely free from moisture, and then 
immersed in linseed oil, is said to be thus prevented from 
splitting : the time of immersion depending on the size, &c. 
Palm oil is preferable to whale oil, because impregnation 
with the latter, although in many instances eligible, causes 



DRY ROT IN TIMBER. 107 

wood to become brittle. It is, however, probable that 
whale oil, when combined with other substances, such as 
litharge, coal pitch, or charcoal, may lose much of that 
effect. As cocoa-nut oil, which is, under low temperature, 
like the oil expressed from the nuts of the palm tree, is 
known to be highly preservative of timber and metallic 
fastenings, we may expect the same result from the latter, 
and thereby avoid that extreme dryness and brittleness 
of the timber which Mr. Strange complained of in the 
Venetian ships that had been seasoned for many years in 
frame under cover. Cocoa-nut oil beat up with shell lime 
or chunam, so as to become putty, and afterwards diluted 
with more oil, is used at Bombay and elsewhere as a 
preservative coat or varnish to plank. It cannot become 
a varnish mthout the addition of some essential oil ; and 
the oil of mustard is used ; which, of course, will produce 
the desired effect. In the first volume of the Abbe 
Eaynal, on the European settlements in the East and 
West Indies, he mentions that an oil was exported from 
Pegu for the preservation of ships; but as he does not 
say what oil, no conclusion can be drawn further than as to 
the probability of its being one of those already noticed. 

Experience has proved that even animal oils are so far 
injurious to timber as to render it brittle, whilst they 
preserve it from rottenness ; and that, on the other hand, a 
mineral salt more or less combined with fatty substances 
does not produce that effect. The staves of whale-oil 
casks become quite brittle, whilst those of beef, pork, and 
tallow barrels remain tough and sound. Ships constantly 
in the Greenland trade have their timbers and planks 



108 PREVENTION AND CUKE OF 

preserved so far as they have become impregnated with 
whale oil. 

Experiments with fish oil prove that of itself, unless 
exposed to sun and air, it may be injurious; that it 
loosens the cohesion of timber; but that animal fai, com- 
bined with saline matter, is preservative. 

Fish oil used alone is ineligible, because capable of 
running into the putrefactive process, unless as a thin 
outside varnish. In hard, sound timber, it will hardly 
enter at all ; and if poured into bore-holes in the heads of 
timbers, it will insinuate itself into the smallest rents or 
cracks, and waste through them. Used alone, or with 
any admixture, it is absorbed and dried quickly on wood 
in a decomposing state or commencing to be dry rotten. 
Used with litharge, it dries after some days; but with 
lamp-black it has scarcely so much tendency to dry as 
when used alone. Paint offish oil and charcoal dries 
very quickly where there is absorption, and the charcoal 
extends its oxidating or drying effect to the fish oil in 
its vicinity. 

We give the following to prove what we have written, 
and also to serve as an example for those who wish to try 
experiments : — 

EXPERIMENTS ON FISH OIL. 

June 9. — Upon a piece of old oak scantling, with its albumam on one 
side in a state of decay, fish oil was poured several times, viz. on this day, 
on June 25, and July 3, which it rapidly absorbed in the decayed part. 

July 26. — It was payed (or mopped) with fish oil and charcoal powder, 
and the following day it was put under an inverted cask. 

October 1. — The end of this piece was covered with a greenish mould. 
This proves that fish oil must be injurious, except where exposed to sun and air 
to dry it. 



DRY ROT IN TIMBER. 109 

A compound of fixed oils and charcoal is liable to 
inflame, but as a thin covering or pigment it may not 
be so. 

The 'petroleum oil-wells, near Prome, in Burmah, have 
been in use from time immemorial. Wood, both for 
ship-building and house-building, is invariably saturated 
or coated with the product of those wells ; and it is stated 
that the result is entire immunity from decay and the 
ravages of the white ant. At Marseilles, and some other 
ports in the Mediterranean, it used to be the practice to 
run the petroleum, which is obtained near the banks of 
the Ehone, into the vacancies between the timbers of the 
vessels, to give them durability. It was sometimes, for 
the conjoint purpose of giving stability and duration to 
vessels, mixed with coarse sand or other extraneous 
matters, and run in whilst hot between the ceiling and 
bottom plank, where it filled up the vacancies between 
the timbers in the round of their bottoms, excepting 
where necessary to be prevented. The great objection 
to the use of petroleum is its inflammability. Creosote, its 
great rival for wood preserving, is also inflammable, and 
not so agreeable in colour ; but it is considerably cheaper, 
which is an important matter. 

As we are now about to enter upon the subject of patent 
processes, &c., it appears desirable to lay down certain 
principles at the commencement, in order to assist the 
reader as much as possible. 

Almost every chemical principle or compound of any 
plausibility has been suggested in the course of the last 
hundred and fifty years ; but the multiplicity and contra- 



110 PREVENTION AND CURE OF 

diction of opinions form nearly an inextricable labyrinth. 
To commence. 

1st. It seems obvious that the sooner the sap is wholly 
removed from the ivood the better, provided the ivoody fibre 
solidifies without injury. 

2nd. That the wood should be impregnated with any 
strongly antiseptic and non-deliquescent matter, ivhich must 
necessarily be in solution when it enters the wood. No deli- 
quescent remedy is eligible, because moisture is injurious 
to metallic fastenings. 

3rd. The wood should be first dried, and its pores then 
closed with any substance impervious to air and moisture, 
and at the same time highly repellant to putrescency. The 
most essential requisites in a preservative of timber being 
a disposition to dryness, and a tendency to resist combustion 
as far as consistently obtainable. 

4th. Any process to be successful ought not to be tedious, 
very difficult, or too expensive. These are important 
elements in the success of any patent. 

Very little is known of any preservative process previous 
to the year 1717, when directions were given by the Navy 
authorities to boil treenails, and dry them before they 
were used. But whether the custom had prevailed before 
this time, or whether their strength and durability were 
increased by it, there are no means of ascertaining. It 
does not appear that any substance was put into the 
water to decompose the juices ; but as they are soluble in 
warm water, perhaps the power of vegetation might have 
been destroyed without it. 

In 1737 ]\[r. Emerson patented a process of saturating 



DRY ROT IN TIMBER. Ill 

timber with loiled oil, mixed with poisonous substances; 
but his process was very little used. This, we believe, 
was the first patent on wood preserving. 

About 1740, Mr. Keid proposed to arrest decay by means 
of a certain vegetable acid (probably pyroligneons acid). 
The method of using it was by simple immersion. 

In 1756, Dr. Hales recommended that the planks at 
the water-line of ships should be soaked in linseed oil, to 
prevent the injury to which wood is subject when alter- 
nately exposed to wet and dry ; and indeed, many ships 
were built in which a hollow place was cut in one end of 
each beam or sternpost, which might constantly be kept 
filled with train oil. Amongst other ships so constructed, 
the Tame/ 74, may be mentioned. When, after some 
years, this ship was repaired, it was found that as far as 
the oil had penetrated, namely, from 12 to 18 inches from 
the end, the w^ood was quite sound, whilst the other parts 
were more or less decayed. The Americans used to hollow 
out the tops of their masts in the form of cups or basins ; 
bore holes from the end a considerable way down the 
masts ; pour oil into these ; cover them over with lead ; 
and leave the oil to find its way down the capillary ves- 
sels to the interior of the timber.* 

In 1769, Mr. Jackson, a London chemist, with a view 
to the prevention .of decay, obtained permission to pre- 
pare some timber to be used in the national yards, by im- 
mersing it in a solution of salt water, lime, muriate of soda^ 
potash, salts, &c., the result of which dose was, that several 
frigates in the Navy subjected to the process were rendered 
* See No. 1, p. 3, Appendix to first volume of 'Naval Architecture.' 



112 PREVENTION AND CURE OF 

more perishable tlian if tliey had been constructed of un- 
prepared timber. The solution was filtered into the wood 
partly by means of holes made in it. Chapman proposed 
a similar method of preserving the frames of ships, viz. by 
boring holes in the timbers, and pumping a solution of 
copperas in water into them. He believed every part of 
the vessel would thus be impregnated. 

Mr. Jackson also prepared the frame of the ship ^ In- 
trepid ' with another solution. The ship lasted many 
years. Bowden thought it was a solution of glue. Chap- 
man suggested slaked lime, thinned with a weak solution of 
glue for mopping the timbers of a ship. 

Shortly after Mr. Jackson's process was started, Mr. 
Lewis attempted to accomplish the preservation of timber 
by placing it surrounded by pounded lime, in spaces below 
the " surface of the earth." The use of lime has also been 
advocated by Mr. Knowles, Secretary of the Committee of 
Surveyors of the Navy, who has written an able work on 
the ' Means to be taken to Preserve the British Navy 
from Dry Rot ' (1821). 

Between 1768 and 1773 a practice prevailed of saturat- 
ing ships with common salt ; but this was found to cause a 
rapid corrosion of the iron fastenings, and to fill the vessels 
between decks with a constant damp vapour. In * Nichol- 
son's Journal,' No. 30, there is an article signed Nauticus 
on this subject. Vessel owners had long ago observed that 
those ships which have early sailed with cargoes of salt 
are not attacked by dry rot. Indeed, several instances are 
attested of vessels whose interiors were lined with fungi 
having all traces of the plant destroyed by accidental or 



DRY ROT IN TIMBER. 11 



o 



intentional sinking in the sea. Acting on such hints, a 
trader of Boston, U. S., salted his ships with 500 bushels 
of the chloride, disposed as an interior lining, adding 100 
bushels at the end of two years. Such an addition of dead 
weight is sufficient objection to a procedure which has 
other great disadvantages. Salt should never be applied 
as an antidote against the dry rot, on account of its natural 
powers of attracting moisture from the atmosphere, which 
would render apartments almost uninhabitable, from their 
continual dampness. Those w ho have lived for any length 
of time in a house at the sea-side, the mortar of which has 
been partly composed of sea sand, will have observed 
the moist state of the paper, plastering, &c., in wet 
weather. Bricks made with sea sand are objectionable. 

Salt water seasoning has already been referred to in the 
last chapter, but as it is so closely connected with salt 
seasoning, the further and final consideration of salt w^ater 
seasoning may be fitly dealt with here. Salt water will not 
extract the juices from the timber like fresh water. It is 
only by destroying the vegetation that salt water can be 
advantageous, but it would require a very long time to im- 
pregnate large timber to the heart so as to destroy vegeta- 
tion. It is well known that wood is softened, and in time 
decomposed, by extreme moisture. Fifty years since, the 
master builder at Cronstadt complained that the oak from 
Casan, which was frequently wet from different causes in its 
passage of three years to Cronstadt, was so water-soaked as 
never to dry ; and also from the information of Mr. Strange, 
it appears "that the practice at Venice of the fresh-cut 
timber being thrown into salt water, prevents its ever 



114 PREVENTION AND CURE OF 

becoming dry in the ships, and that the salt Avater rusted 
and corroded the iron bolts." In fine, vessels built with 
salt water seasoned wood are perfect hygrometers, being as 
sensible to the changes of the moisture of the atmosphere 
as lumps of rock salt, or the plaster of inside w^alls where 
sea sand has been used. 

In Ceylon, the timber of the female palm tree is much 
harder and blacker than that of the male^ inasmuch as it 
brings nearly triple its price. The natives are so well 
aware of the difference that thev resort to the devise of 
immersing the male tree in salt water to deepen its colour, 
as well as add to its weight. 

Vessels impregnated wdth lay salt, or the large grained 
salt of Leamington or of Liverpool (pure muriate of soda)^ 
will possess decided advantages ; as also will vessels that 
have been laden with saltpetre, if it has been dispersed 
amongst their timbers. 

Ships (the timbers of which had been previously im- 
mersed in salt water) have been broken up after a few 
years' service, and the floor timbers taken out quite sound : 
but when exposed to the sun and rain in the summer 
months, their albumen has been in a decomposed or 
friable state. 

By the answers to queries given to Mr. Strange, the 
British Minister at Venice, in or about 1792, it appears 
that several of the Venetian ships of war had then lain 
under sheds for fifty-nine years ; some in bare frames, and 
others planked and caulked: that these ships show no 
outward marks of decay ; but their timbers have shrunk 
much, and become brittle ; that some of the most intelligent 



DRY ROT IN TlilBEB. 115 

ship builders were of opinion that great prejudice had 
arisen from the prevalent custom of throwing the timber 
fresh cut into salt water, and letting it lie there until 
wanted ; that afterwards it dried, and withered on the 
outside, under the sheds, w^hile the inside, being soaked 
with salt water, rotted before it became dry ; and this was 
one reason, amongst others, why Venetian ships, though 
built of good timber, lasted so short a time ; for the salt 
moisture not only rots the inside of the beams and timbers, 
but of course rusts and corrodes the iron bolts. 

Salt water, sea-sand, and sea-weed are now used for 
seasoning "jarrah" wood in Western Australia. This 
wood is considered a first-class wood for shipbuilding, but 
it is somewhat slow to season, and if exposed before being 
seasoned it is apt to " fly " and cast. The method adopted is 
as follows : The logs are thrown into the sea, and left there 
for a few weeks ; they are then drawn up through the sand, 
and after being covered with sea-weed a few inches deep, 
are left to lie on the beach, care being taken to prevent 
the sun getting at their ends. The logs are then left for 
many months to season. When taken up they are cut 
into boards 7 inches wide, and stacked, so as to admit of a 
free circulation of air round them, for five or six months 
before using them. Sea-weed or sea-ware, cast upon the 
shores, contains a small quantity of carbonate of soda, and 
a large proportion of nitrogenous and saline matters, with 
earthy salts, in a readily decomposable state. They also 
contain much soluble mucilage. The practice of seasoning 
timber by heating it in a sand hath was formerly adopted 
by the Dutch, and by the Kussians in building boats. 

I 2 



116 PREVENTION AND CURE OF 

Mr. Thomas Nichols (in a letter to Lord Chatham, when 
First Lord of the Admiralty) states '' that the same end, 
viz. preservation of timber from decay, might probably 
be acquired by burying the timber in sand, which acts as 
an artificial sap," in the same manner as mentioned in 
Townsend's ' Travels through Spain,' to be used with the 
masts of ships of war at Cadiz. 

Peat moss has been recommended (because the sulphates 
of iron, soda, and magnesia are found in it)^ but it failed 
when tried. 

With reference to Mr, Lewis's proposal to preserve wood 
by means of lime, it must be remembered that quichUme, 
with damp, has been found to accelerate putrefaction, in 
consequence of its extracting carbon ; but when dry, and 
in such large quantities as to absorb all moisture from the 
wood, the wood is loreserved^ and the sap hardened, Ves^ 
sels long in the lime trade have afforded proof of this fact; 
and we have also examples in plastering-laths, which are 
generally found sound and good in places where they have 
been dry. Whitewash or limewater has been strongly 
recommended for use between the decks of ships, as being 
unfavourable to vegetation : it should be renewed at in- 
tervals of time, according to circumstances. It has been 
applied with good effect to the joists and sleepers of 
kitchen floors ; but to be effectual it should be occasion- 
ally renewed. Effete, or re-carbonated lime, is injurious 
to timber, like other absorbent earths ; so also are calca- 
reous incrustations formed by the solution of lime in water, 
as appears from Von Buch's ' Travels in Norway,' in which 
he says, *' that in the fishing country (near Lofodden, 



DRY ROT IN TIMBER. 117 

beyond the Arctic circle) the calcareous incrustations 
brought by water, filtering through a bed of shells, soon 
cause the vessels and wood to be covered with and destroyed 
by green fungi." The ends of joists of timber inserted in 
walls are frequently found rotten ; and where not so, it 
may probably be owing to the mortar having been made 
with hot lime, and used immediately, or to the absence of 
moisture. It does not appear practicable to use limewater 
to any extent for preserving timber, because water holds 
in solution only about ^^^o^h part of lime, which quantity 
would be too inconsiderable ; it, however, renders timber 
more durable, but at the same time very hard and difficult 
to be worked (p. 73). 

Vessels constantly in the coal trade have generally re- 
quired little repair, and have lasted until in the common 
course of things they were lost by shipwreck. This must 
be owing to the martial pyrites which abound in all coals ; 
and also from the sulphuric acid arising from the quantity 
of coal dust which finds its way through the seams of the 
ceiling, and adheres to the timber and planks. 

In 1779, M. Pallas, in Kussia, proposed to steep wood 
in sulphate of iron (green vitriol) until it had penetrated 
deeply, and then in lime to precipitate the vitriol. Neu- 
mann, in his first volume of ' Chemistry,' on the article 
green vitriol, says, " That in the Swedish transactions this 
salt is recommended for preserving wood, particularly the 
wheels of carriages, from decay. 

^' When all the pieces are fit for being joined together, 
they are directed to be boiled in a solution of vitriol for 
three or four hours, and then kept for some days in a 



118 PREVENTION AND CURE OF 

warm place to dry. It is said that the wood by this pre- 
paration becomes so hard and compact that moisture can- 
not penetrate it, and that iron nails are not so apt to be 
destroyed in this vitriolated wood as might be expected, 
htd last as long as the wood itself r 

In 1780 the marcasite termed by the miners mundic, 
found in great abundance in the tin mines in Devonshire 
and Cornwall, was employed, in a state of fusion, to eradi- 
cate present and to prevent the future growth of dry rot ; 
but whether its efficacy was proved by time is not known. 
A garden walk where thei'e are some pieces of mundic 
never has any weeds growing ; the rain that falls becomes 
impregnated with its qualities, and in flowing through the 
walk prevents vegetation. 

In 1796 Hales proposed to creosote the treenails of ships : 
this was forty-two years previous to BethelFs patent for 
creosoting wood. 

About the year 1800, the Society of Arts' building in the 
Adeiphi, London, being attacked by dry rot, Dr. Higgins 
examined the timbers, caused some to be removed and 
replaced by new, and the remainder to be scraped and 
washed with a solution of caustic ammonia^ so as by burning 
the surface of the wood to prevent the growth of fungi. 

At the commencement of the present century, a mem- 
ber of the Eoyal Academy of Stockholm called attention 
to the use of alum for preserving wood from fire. He 
says, in the Memoirs of that Academy, "liaving been 
within these few years to visit the alum mines of Loswers, 
in the province of Calmar, I took notice of some attempts 
made to burn the old staves of tubs and pails that had 



DRY ROT IN TIMBER. 119 

been used for the alum works. For this purpose they were 
thrown into the furnace, but those pieces of wood which 
had been penetrated by the alum did not burn, though 
they remained for a long time in the fire, where they only 
became red ; however, at last they w^ere consumed by the 
intenseness of the heat, but they yielded no flame." He 
concludes, from this experiment, that wood or timber for 
the purpose of building may be secured against the action 
of fire by letting it remain for some time in water w^herein 
vitriol, alum, or any other salt has been dissolved w^hieh 
contains no inflammable parts. 

In Sir John Pringle's Tables of the antiseptic powers of 
different substances, he states alum] to be thirty times 
stronger than sea-salt ; and by the experiments of the 
author of the ' Essai pour servir a FHistoire de la Putre- 
faction,' metallic salts are much more antiseptic than 
those with earthy bases. 

In 1815 it occurred to Mr. Wade that it would be a 
good practice to fill the pores of timber with alumine, 
or selenite; but two years after. Chapman observed, 
" Impregnation of ships' timbers with a solution of alum 
occurred to me about twenty years since, because on im- 
mersion in sea-water the alumine would be deposited in 
the pores of the timber ; but I was soon informed of its 
worse than inutilily, by learning that the experiment had 
been tried, and, in place of preserving, had caused the wood 
to rot speedily. Impregnation with selenite has been tried 
in elm water-pipes. On precipitation from its solvent it 
partially filled the pores, and hardened the wood, but occa- 
sioned ' speedy rottenness^ If, by using a solution of alum 



120 PREVENTION AND CURE OF 

to render wood uninflammable, we at the same time cause 
it to rot speedily, it becomes a question luhether the remedy 
is 7iot worse than the disease. Captain E. M. Shaw, of the 
London Fire Brigade, in his work, ^ Fire Surveys ' (1872)^ 
recommends alum and ivater. Probably he only thought 
of fire, and not of rotting the wood. The alum question 
does not appear to be yet satisfactorily settled. 

While upon the subject of uninflammable wood, we may 
state that in 1848, upon Putney Heath (near London), by 
the roadside^ stood an obelisk, to record the success of a 
discovery made in the last century of the means of build- 
ing a house which no ordinary application of ignited com- 
bustibles could be made to consume : the obelisk was 
erected in 1786. The inventor was Mr. David Hartley, 
to whom the House of Commons voted 2500Z., to defray 
the expenses of the experimental building, which stood 
about one hundred yards from the obelisk. The building 
was three stories high, and two rooms on a floor. In 
1774, King George the Third and Queen Charlotte took 
their breakfast in one of the rooms, while in the apartment 
beneath fires were lighted on the floor, and various inflam- 
mable materials were ignited to attest that the rooms above 
were fire-proof. Hartley's secret lay in the floors being 
double, and there being interposed between the two 
boards sheets of laminated iron and copper, not thicker 
than stout paper, which rendered the floor air-tight and 
thereby intercepted the ascent of the heated air ; so that, 
although the inferior boards were actually charred, the 
metal prevented the combustion taking place in the upper 
flooring. Six experiments were made by Mr. Hartley in 



DRY ROT IN TIMBER. 121 

this house in 1776, but we cannot ascertain any particulars 
about them, or any advantages which accrued to the 
public from the invention, although the Court of Common 
Council awarded him the freedom of the City of London 
for his successful experiments. 

In 1805 Mr. Maconochie proposed to saturate with re- 
sinous and oily matters inferior woodsj and thus render them 
more lasting. This proposal was practically carried out 
in 1811 by Mr. Lukin, who constructed a peculiar stove 
for the purpose of thus impregnating wood under the in- 
fluence of an increased temperature. The scheme, how- 
ever, had but very partial success, for either the heat was 
too low and the wood was not thoroughly aired and sear 
soned, or it was too high and the wood was more or less 
scorched and burnt. Mr. Lukin buried wood in pulverized 
charcoal in a heated oven, but the fibres were afterwards 
discovered to have started from each other. He next 
erected. a large kiln in Woolwich dockyard, capable of\ 
containing 250 loads of limber, but an explosion took 
place on the first trial, before the process was complete, 
which proved fatal to six of the workmen, and wounded 
fourteen, two of whom shortly afterwards died. The 
explosion was like the shock of an earthquake. It demo- 
lished the wall of the dockyard, part of which was thrown 
to the distance of 250 feet ; an iron door weighing 280 lb. 
was driven to the distance of 230 feet ; and other parts of 
the building were borne in the air upwards of 300 feet. 
The experiment was not repeated. 

Mr. Lukin was not so fortunate in 1811 as in 1808, for 
in the latter year he received a considerable reward from 



122 PBEVENTION AND CURE OF 

the Government for what was considered a successful 
principle of ventilating hospital ships. 

In 1815 Mr. Wade recommended the impregnation of 
timber with resinous or oleaginous matter (preferring lin- 
seed oil to whale oil) or with common resin dissolved in a 
lixivium of caustic allcali, and that the timber should after- 
wards be plunged into water acidulated with any cheap 
acid, or with alum in solution. He considered that timber 
impregnated with oil would not be disagreeable to rats, 
worms, cockroaches, &c., and that the contrary was the 
case with resin. He also recommended the impregnation 
of timber with sulphate of copper, zinc, or iron, rejecting 
deliquescent salts, as they corrode metals. 

In 1815 Mr. Ambrose Boydon, of the Navy Office, 
strongly recommended that the timber, planks, and tree- 
nails of ships should be first boiled in limewater to correct 
the acid, and that they afterwards should be boiled in a 
thin solution of glue, by which means the pores of the wood 
would be filled with a hard substance insoluble by water, 
which would not only give the timbers durability, by pre- 
venting vegetation, but increase their strength. Glue, he 
thought, might be used without limewater, or glue and 
limewater mixed together. 

In 1817 Mr. William Chapman published the result of 
various experiments he had made on wood with lime, soap, 
and alkaline and mineral salts. He recommended a solu- 
tion of a pound of sulphate of copper or blue vitriol (at 
that time Id. per pound) dissolved in four ale gallons of 
rain water, and mopped on hot over all the infected parts, 
or thrown over them in a plentiful libation. He also re- 



DRY ROT IN TIMBER. 12 



Q 



commended one ounce of corrosive sublimate (then Gs. per 
pound) to a gallon of rainwater applied in the same man- 
ner to the infected parts. For weather-boarded buildings 
he considered one or more coats of thin coal tar, com- 
bined with a small portion of jpalm oil, for the purpose of 
preventing their tendency to rend, to be a good pre- 
servative. 

Messrs. Wade, Boydon, and Chapman published works 
on dry rot about this time. 

In 1822 Mr. Oxford took out a patent for an improved 
method of preventing " decay of timber," &c. The pro- 
cess proposed was as follows : " The essential oil of tar was 
first extracted by distillation, and at the same time satu- 
rated with chlorine gas. Proportions of oxide of lead^ 
carbonate of lime, and carbon of purified coal tar well 
ground, were mixed with the oil, and the composition 
was then applied in thick coatings to the substances in- 
tended to be preserved. 

On 31st March, 1832, Mr. Kyan patented his process of 
corrosive sublimate (solution of the bi-chloride of mercury) 
for preventing dry rot ; which process consisted as follows : 
A solution of the corrosive sublimate is first made, and the 
timber is placed in the tank. The wood is held down in 
such a way, that when immersed on tlie fluid being pumped 
in, it cannot rise, but is kept under the surface, there being 
beams to retain it in its place. There it is left for a week, 
after which the liquor is pumped off, and the wood is re- 
moved. This being done, the timber is dried, and said to 
be prepared. Sir Eobert Smirke was one of the first to use 
timber prepared by Kyan, in some buildings in the Temple, 



124 PKEVENTION AND CURE OF 

London; and he made some experiments on timber 
which had undergone Kyan's process. He says, " I took 
a certain number of pieces of wood cut from the same log 
of yellow pine, from poplar, and from the common Scotch 
fir ; these pieces I placed first in a cesspool, into which the 
waters of the common sewers discharged themselves ; they 
remained there six months ; they were then removed from 
thence, and placed in a hotbed of compost, under a garden- 
frame; they remained there a second six months; they 
were afterwards put into a flower border, placed half out 
of the ground, and I gave my gardener directions to water 
them whenever he watered the flowers ; they remained 
there a similar period of six months. I put them after- 
wards into a cellar where there was some dampness, and 
the air completely excluded ; they remained there a fourth 
period of six months, and were afterwards put into a very 
wet cellar. Those pieces of wood which underwent 
Kyan's process are in the same state as when I first had 
them, and all the others to which the process had not 
been applied are more or less rotten, and the poplar is 
wholly destroyed. 

"I applied Kyan's process to yellow Canadian pine 
about three years ago, and exposed that wood to the 
severest tests I could apply, and it remains uninjured, 
when any other timber (oak or Baltic wood) would cer- 
tainly have decayed if exposed to the same trial, and not 
prepared in that manner. 

" As another example of the effect of the j)rocess, I 
may mention that about two years ago, in a basement 
story of some chambers in the Temple, London, the wood 



DRY ROT IN TIMBER. 125 

flooring and the wood lining of the walls were entirely 
decayed from the dampness of the ground and walls, and 
to repair it under such circumstances was useless. As I 
found it extremely difficult to prevent the dampness, I 
recommended lining the walls and the floor with this pre- 
pared wood, which was done ; and about six weeks ago I 
took down part of it to examine whether any of the wood 
was injured, but it was found in as good a state as 
when first put up. I did not find the nails more liable 
to rust.' 

"I have used Kyan's process in a very considerable 
quantity of paling nearly three years ago ; that paling is 
now in quite as good a state as it was, though it is partly 
in the ground. It is yellow pine. Some that I put up 
the year before, without using Kyan's process (yellow pine), 
not fixed in the ground, but close upon it, is decayed." 
"^ This evidence, by such an experienced architect as the 
late Sir Eobert Smirke was, is certainly of great value in 
favour of Kyan's process. 

The recorded evidence upon the efficiency of this mode 
of treating timber for its preservation is somewhat contra- 
dictory. On the Great Western Kailway 40,000 loads 
were prepared, at an expenditure of If lb. of sublimate 
to each load, the timber, 7 inch, being immersed for a 
period of eight days, and the uniformity of the strength of 
the solution being constantly maintained by pumping. 
Some samples of this timber, after six years' use as 
sleepers on the railway, were found '^ as sound as on the 
day on which they were first put down." This timber 
was prepared by simple immersion only, without ex- 



12t) PREVENTION AND CUBE OF 

haustion or pressure. Some of the sleepers on the London 
and Birmingliam Railway, on the other hand, which had 
been Kyanized three years only^ were found absolutely 
rotten, and Kyan's process was there consequently 
abandoned. 

This process is said to cost an additional expense to 
the owner of from fifteen to twenty shillings per load of 
timber. Mr. Kyan at first used 1 lb. of the salt in 4 
gallons of water, but it was found that the wood absorbed 
4 or 5 lb. of this salt per load ; more water was added to 
lessen the expense, until the solution became so weak as 
in a great measure to lose its effect. 

Simple immersion being found imperfect as a means of 
injecting the sublimate, attempts were afterwards made 
to improve the efficiency of the solution hy forcing it into 
the wood. Closed tanks were substituted for the open 
ones, and forcing pumps, &c., were added to the apparatus. 
The pressure applied equalled 100 lb. on the square inch. 
With this arrangement a solution was made use of having 
1 lb. of the sublimate to 2 gallons of water ; and it was 
found that three-fourths of this quantity sufficed for pre- 
paring one load of timber. The timber was afterwards 
tested, and it was ascertained that the solution had pene- 
trated to the heart of the logs. Mr. Thompson, the 
Secretary to Kyan's Company, stated, in March, 1842, 
that experience had proved "that the strength of the 
mixture should not be less than 1 lb. of sublimate to 
15 gallons of water ; and he had never found any well- 
authenticated instance of timber decaying when it had 
been properly prepared at that strength." As much 



PATENT PRESERVATIVE SYSTEiVI 




iiG "M^ m' mc ""^ ^ ' W^ m^ 



Ilorizontiil Section of AF Kyans Original Taiik and CisU*m 



A. Baitoni of Tank 

B. % IrcTh h()U.< (jp t'inin£4,'t th^pljanJx.s which fbrrn fh^ side^ a/uC p/iJ oi' thf 
TaJifv and Ci/itftn . 

C. The/ Cist^f-n wliirh ccnUiins tJif" sohxtCow. 
1). The Taidi 

E. frunp irr raisiny (he .<irbiUvu H (jin lank-uiU? Cistefii 

F . Tap fvr ccTtvtyina fhje soJjuUcit fronu Cisf^rn to Tank . 

G. Woodj sleepers to ccury Taidv ojuIj Cistern . 



DRY ROT IN TIMBER. 127 

as 1 in 9 was not unfrequently used. Kyan's process is 
now but very rarely used ; Messrs. Betliell, of King 
William Street, London, adopt it when requested by their 
customers. We have given the statements which have 
been made for and against this patent, but after a lapse 
of forty years it is diflScult to reconcile conflicting 
statements 

Although Mr. Kyan invented his process in 1832, Sir 
Humphrey Davy had previously used and recommended 
to the Admiralty, and Navy Board, a weak solution of 
the same thing to be used as a wash where rot made its 
appearance : on giving his opinion upon Mr. Lukin's 
process, that eminent chemist observed, " that he had 
found corrosive sublimate highly antiseptic, and preser- 
vative of animal and vegetable substances, and therefore 
recommended rubbing the surface of timber with a solu- 
tion of it." In 1821 Mr. Knowles, of the Navy Office, 
referred to the use of corrosive sublimate for timber. In 
fact, it was used in 1705, in Provence (France), for pre- 
serving wood from beetles. Kyan, however, was the first 
to apply it to any extent. In the years 1833 to 1836, 
at the Arsenal, Woolwich, experiments were instituted, 
having for their object the establishing, or otherwise, the 
claims of Kyan's system ; the results of which were of a 
satisfactory nature. Dr. Faraday has stated that the com- 
bination of the materials used was not simply mechanical 
but chemical ; and Captain Alderson, C.E., having experi- 
mented upon some specimens of ash and Christiana deal, 
found that the rigidity of the timber was enhanced, but 
its strength was in some measure impaired ; its specific 



128 PEEVENTION AND CURE OF 

gravity being also in some degree diminished * Kyan's 
process is said by some to render the wood brittle. 

Mr. Kyan considered that the commencement of rot 
might be stopped or prevented by the application of 
corrosive sublimate, in consequence of the chemical 
combination which takes place between the corrosive sub- 
limate and those albuminous particles which Berzelius and 
others of the highest authority consider to exist in and 
form the essence of wood ; which, being the first parts to 
run to decay, cause others to decay with them. By 
seasoning timber in the ordinary way, the destructive 
principle is dried, and under common circumstances 
rendered inert. But when the timber is afterwards 
exposed to great moisture, &c. (the fermentative principle 
being soluble when merely dried), it will sometimes be 
again called into action. Kyan's process is said not only 
altogether to destroy this principle and render it inert, 
but, by making it solid and perfectly insoluble, to remove 
it from the action of moisture altogether. It thus loses 
its hygrometric properties, and, therefore, prepared or 
patent seasoned timber is not liable to those changes oi 
atmosphere which affect that w^iich is seasoned in the 
common way. All woods, including mahogany and the 
finest and most expensive wood, may be seasoned by 
Kyan's process in a very short space of time, instead of 
the months required by the ordinary methods. 

The reader will find a great deal about Kyan's system 
in the ' Quarterly Review,' April, 1833 ; and about pro- 

♦ See paper on " Kyan's Process/' by Captain R. C. Aldcrson, C.E., in 
vol. i. * Papers of Royal Engineers.' 



DRY ROT IN TBIBER. 129 

posals for using chloride of mercury for wood, ' Memoirs of 
the Academy of Dijon,' 1767 ; ' Bull, des Sciences teen.,' 
V. ii., 1824, Paris ; and ' Bull, de Pharm.,' v. 6, 1814, Paris. 

It is well known that Canadian timber is much more 
liable to decay than that grown in the northern parts of 
Europe, and for this reason is never extensively used in 
buildings of a superior description. The principle of decay 
being destroyed by Kyan's process as above described, this 
objection no longer exists, and this kind of timber may 
therefore now be employed with as great security as that 
of a superior quality and higher price. The same obser- 
vation applies with great force to timber of British growth, 
particularly to that of Scotland, much of which is con- 
sidered as of little or no value for durable purposes, on 
account of its extreme liability to decay, whether in 
exposed situations or otherwise. The process invented by 
Kyan might therefore render of considerable value plan- 
tations of larch, firs of all kinds, birch, elm, beech, ash, 
poplar, &c. 

Cost of process in 1832, 1/. per load of 50 cubic feet of 
timber. 

Mr. W. Inwood, tlie architect of St. Pancras Cliurch, 
London, reported favourably of Kyan's process. On 22nd 
February, 1833, Professor Faraday delivered a lecture at 
the Eoyal Institution, London, on Kyanizing timber ; and 
on 17th April, 1837, he reported that Kyan's process 
had not caused any rusting or oxidation of the iron in 
the ship ^Samuel Enderby,' after the ship had been 
subjected to this process, and had been on a three yea^^s' 
voyage to the South Sea fisheries ; and in the same year, 

K 



130 PREVENTION AND CUEE OF 

viz. 1837, Dr. Dickson delivered a lecture at the Eoyal 
Institute of British Architects on dry rot, recommending 
Kyan's process. 

Five years after Mr. Kyan's invention, viz. in 1837, a 
Mr. Flocton invented a process for preventing decay, by 
saturating timber with ivood-tar and acetate of iron, but 
little is known of this invention : we believe it was a 
failure. 

During the same year Mr. Flocton's process was made 
known, a Frenchman named Letellier recommended 
saturating timber in a solution of corrosive sublimate, and 
when dry, into one of glue, size, &c.* 

During this year Mr. Margary took out his patent for 
applying sulphate of cojpper to wood. We propose to de- 
scribe Margary 's process further on : we do not think he 
received any medals for it. 

We now arrive at the modern creosoting process, which 
was brought to perfection by the late Mr. John BethelL 
Mr. Bethell's process of creosoting, or the injection of the 
heavy oil of tar, was first patented by him on July 11th, 
1838.t It consists in impregnating the wood throughout 
with oil of tar, and other bituminous matters containing 
creosote, and also with pyrolignite of iron, which holds 
more creosote in solution than any other watery men- 
struum. Creosote, now so extensively used in preserving 
wood, is obtained from coal tar, which, when submitted 
to distillation, is found to consist of pitch, essential oil 



* See Chapman, Boydon, Jackson, and Kyan's methods, 
t See * London Journal of Arts,' March, 1842 ; * Bull, de I'Encourage- 
ment,' June, 1842. 



DRY ROT IN TIMBER. 131 

(creosote), naphtha, ammonia, &c. In the application 
of the oil of tar for this purpose, it is now considered 
to be indispensable that the ammonia be got rid of; 
otherwise the wood sometimes becomes brown and do- 
cays, as may be constantly seen in wood coated with 
the common oil tar. The kind of creosote preferred 
by continental engineers and chemists, and also by the 
late Mr. John Bethel! himself, is thick, and rich in najph- 
thaline. Some English chemists now seeia to prefer the 
thinnest oil, which contains no naphthaline, but a little 
more carbolic acid ; the crude carbolic acid w^ould vary 
from 5 to 15 per cent. : no engineer has ever required 
more than 5 per cent, of crude carbolic acid in creosote. 
The thinner oil appears to be more likely to be drawn 
out of the wood by the heat of the sun or absorption in 
powdery soil, and is more readily dissolved out by moisture. 
Mummies many thousands of years old have evidently 
been preserved on the creosoting principle, and from 
observing the mummies the process of creosoting sug- 
gested itself to Mr. Bethell. The ancient Egyptians, 
whether from the peculiarity of their religious opinions, 
or from the desire to shun destruction and gain perpe- 
tuity even for their dead bodies, prepared the corpses of 
their deceased friends in a particular way, viz. by coagu- 
lating the albumen of the various fluids of the body by 
means of creosote, cedar oil, salt, and other substances, 
and also by excluding the air. How perfectly this 
method has preserved them the occasional opening of a 
mummy permits us to see. A good account of the opera- 
tion is given in the chapter on mummies, in the second 

K 2 



132 PBEYENTION AND CURE OF 

volume of Egyptian Antiquities in the 'Library of Enter- 
taining Knowledge.' 

By the process of creosoting the timber is rendered 
more durable, and less liable to the attack of worms ; but 
it becomes very inflammable; tliat is, when once alight 
burns quickly; in addition to which, the disagreeable 
odour from timber so treated renders it objectionable for 
being used in the building of dwelling-houses. 

The action of the solutions in water of metallic salts 
is, if the mixture is sufficiently strong, to coagulate the 
albumen in the sap ; but the fibre is left unprotected. 

Creosote has the same effect of coagulating the albu- 
men, whilst it fills the pores of the wood with a bitu- 
minous asphaltic substance, which gives a waterproof 
covering to the fibre, prevents the absorption of water, 
and is obnoxious to animal life. 

In cases where (he complete preservation of timber is 
of vital importance, and expense not a consideration, the 
wood should be first subjected to Burnett's process, and 
then creosoted ; by which means it would be nearly inde- 
structible ; the reason for this combined process being, 
that the albumen or sap absorbs the creosote more readily 
than the heart of the timber, which can, however, be 
penetrated by the solution of chloride of zinc. Mr. John 
Bethell's patent of 1853 recommends this in a rather 
improved form. He says the timber should first be 
injected with metallic salts, then dried in a drying-house, 
then creosoted. By this method, very considerable quan- 
tities both of metallic salt and creosote can be injected 
into timber. 



DRY ROT IN TIMBER. 133 

It has been stated that the elasticity of wood is in- 
creased by creosoting ; the heartwood only decays by 
oxidation. 

The wood should be dried previous to undergoing the 
process, as the sapwood, otherwise almost useless, can be 
rendered serviceable, and for piles for marine work whole 
round timber should be used, because the sapwood is 
so much more readily saturated with the oil, and this 
prevents the worms from making an inroad into the 
heart. 

Mr. Bethell uses about 10 lb. of creosote per cubic 
foot of wood, and he does not allow a piece of timber to 
be sent from his w^orks without being tested to ascertain 
if it has absorbed that amount, or an amount previously 
agreed upon. We mention the latter statement, because 
it is evident that all descriptions of wood cannot be made 
to^imbibe the same amount. This process is chiefly used 
for pine timber: yellow pine should absorb about 11 lb. 
to the cubic foot, and Riga pine about 9 lb. The quan- 
tity of oil recommended by the patentee, engineers, and 
others, is from 8 to 10 lb. for land purposes, and about 
12 lb. to the cubic foot for marine. In this country, for 
marine the quantity does not exceed 12 lb. ; but on the 
Continent, in France, Belgium, and Holland, the quantity 
used is from 14 to 22 lb. ( ! ) per cubic foot. The specifi- 
cations frequently issued by engineers for sleepers for 
foreign railways describe them to be entirely of heart- 
wood, and then to be creosoted to the extent of 10 lb. of 
the oil per cubic foot : this it is impossible to do, the value 
of the process being in the retention of the sapwood. 



134 PREVENTION AND CURE OF 

It being ascertained a few years since that the centres 
of some sleepers were not impregnated with the fluid, 
after the sleeper had been creosoted to the extent of 
10 lb. of creosote per cubic foot, Sir Macdonald Stephen- 
son suggested, as a means of obviating that defect, the 
boring of two holes, 1 inch in diameter, through each 
sleeper longitudinally, and impregnating up to 12 lb. or 
14 lb. per cubic foot. By that means the creosote would 
be sent all tlirough the sleeper. The boring by hand 
would be an expensive process, but by machinery it might 
be effected at a comparatively small increased cost. 

During the last twenty-five years an enormous quantity 
of creosoted railway sleepers have been sent to India and 
other hot climates. The native woods are generally too 
hard for penetration. On the great Indian Peninsula 
Railway the native woods were so hard and close-grained 
that they could not be impregnated with any preserva- 
tive substance, sal wood being principally used, into which 
creosote would not penetrate more than one quarter of an 
inch. As regards creosoting wood in India, it is moreover 
a costly process, owing to the difficulty and expense of 
conveying creosote from England ; iron tanks are neces- 
sary to hold the oil when on board ship, and, being 
unsaleable in India, add to the expense. 

English contractors often send piles to be creosoted 
which have been taken from the timber docks. The large 
quantity of water they contain resists the entrance of the 
oil, and the result is that a great deal of timber is badly 
prepared because the contractors cannot obtain it dry. 

In the best creosoting works the tank or cylinder is about 



DHY EOT IN TIMBER. 135 

6 feet diameter, and from 20 to 50 feet long. In some 
instances cylinders are open at both ends, and closed with 
iron doors, so that sleepers or timber entered at one end 
on being treated can be delivered finished at the opposite 
end ; but for all practical purposes one open end is suffi- 
cient, as the oil when heated being of such a searching 
character it is a difficult matter to get the doors perfectly 
air-tight, consequently they are apt to leak during the 
time the pressure is being applied. Pipes are led from 
the cylinder to the air and force pumps; the air is not 
only extracted from the interior of the cylinder, but also 
from the pores of the timber. AYhen a vacuum is made, 
the oil, which is contained in a tank below the cylinder, 
is allowed to rush in, and, as soon as the cylinder is full, the 
inlet pipe is shut and the pressure pumps started to force 
the oil into the w^ood; the pressure maintained is from 
150 to 200 lb. to the square inch, until the wood has 
absorbed the required quantity of oil, which is learned by 
an index gauge fixed to the working tank below. All 
cylinders are fitted with safety valves, which allow the oil 
not immediately absorbed to pass again into the tank. 
The oil is heated by coils of pipe placed in the tank, 
through which a current of steam is passed from end to 
end, raising the temperature to 120°. 

With regard to the cost of creosoting: half-round 
sleepers, being 9 feet long, 10 inches wide, and 5 inches 
thick, properly creosoted, are worth about 4s. each ; adzing 
for the chairs (done by machine) costs 6s. per 100. These 
prices, unfortunately, vary very much, according to circum- 
stances. The fir sleepers on the London and Birmingham 



136 PREVENTION AND CURE OF 

Kailway cost 7s. 6d, each, and the patent preservative 
added 9d. more to the expense, but they did not cost so 
much on other lines A London builder wrote to us in 
1870, as follows : " Our price for creosoting timber, &c., 
is 15s. per load of 50 cubic feet. Price of creosote, 2d. 
per gallon." 

By returns from the Leith Harbour Works it was 
shown that the average quantity of creosote absorbed by 
the timber was 57| gallons per load, or 577 lb. weight 
forced into 50 cubic feet of wood. Assuming the cost to 
be 15s. per load, and the creosote at 2d. per gallon, the 
creosote would cost 9s. 8d., and the labour and profit 
5s. 4:d. per load of 50 cubic feet. 

It is essential to observe that all methods of protecting 
timber depend for their success upon the skilful and con- 
scientious manner in which they are applied ; for, as they 
involve chemical actions on a large scale, their efficiency 
must depend upon the observance of the minute practical 
precautions required to exclude any disturbing causes. 
In the case of creosoting: to distil the creosote, to draw 
the sap or other moisture from the wood, and subsequently 
to inject the creosote in a proper manner, it is necessary 
that the operations should be carried into effect under the 
supervision of experienced persons of high character. 

Mr. BethelFs process has been and still is being tested 
on the Indian railways. According to Dr. Cleghorn, it 
appears that many of the creosoted sleepers have, how- 
ever, "been found decayed in the centre, the interior 
portion being scooped out, leaving nothing but a decep- 
tive shell, in some instances not more than ^ inch in 



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DRY ROT IN TIMBER. 137 

tliickness," but he does not state whether the sleepers 
were prepared in England or in India; because, if pre- 
pared in India, it is probable that some of the hard Indian 
woods, into which it is not possible to get creosote or any- 
other preservative fluid, had been used. Mr. Burt, who 
has large timber-preserving works in London for creosot- 
ing, stated about eight years since, that after an experience 
of twenty years, during which time he had sent over one 
million and a half sleepers to India alone, besides having 
prepared many thousand loads of timber for other pur- 
poses, he could safely assert that the instances of failure 
had been rare and isolated. 

A section of a piece of timber impregnated with creosote 
presents some curious and very distinctive characteristics, 
according to the duration of the process of injection and 
amount of tar injected. In eveiy case the injected tar 
follows the lines and sinuosities of the longitudinal fibres. 
When injected in sufficient quantity it fills the pores 
altogether ; when, on the contrary, the process has been 
incompletely performed, which, however, is generally suf- 
ficient, the tar accumulates in the transverse sections, and 
plugs the channels that give access to deleterious agents. 

The experiments made by M. Melseuns on oaken blocks 
exposed to the fumes of liquid ammonia show that the 
conservating fluids follow the precise course that would be 
taken by decay. In wood treated wath creosote the tar 
acts on the very parts first exposed to injury, and on the 
course that would be taken by decay, which is thus ren- 
dered impossible. The methods of injection suggested 
by M. Melseuns in 1845 did not answer equally well 



138 PREVENTION AND CURE OF 

with every kind of wood. After trying wooden blocks 
in every sort of condition, dressed and in the roughs 
green and dry, sound and decayed, M. Melseuns found 
that alder, birch, beech, hornbeam, and willow were easily 
and completely impregnated ; deal sometimes resisted the 
process, the innermost layers remaining white; poplar 
and oak offered a very great resistance — indeed, with 
poplar it was found necessary to repeat the process. 

The decay of sleepers, prepared and unprepared, will 
often depend on their form. Three forms have been used : 
1st, the half-round sleeper, 10 inches by 5 inches; 
these are now almost universally used ; 2nd, the triangular 
sleeper, about 12 inches wide on each side, used by Mr. 
Cubitt on the Dover line, but since abandoned ; and 3rd, 
the half square, 14 inches by 7 inches, used by Mr. Brunei 
and still in use. Mr. G. O. Maun, in reporting on the 
state of the sleepers of the Pernambuco Eailway, states 
that fair average samples taken out on the 1st December, 
1863 (laid in 1857), show that the half-round intermediate 
sleeper is in the most perfect state of preservation ; in fact, 
nearly as good as on the day it was put down ; while the 
square-sawn or joint sleeper has not withstood the effects 
of the climate so well. 

The kind of ballast in which it will be most advisable 
to lay the sleeper is another important point to be 
attended to. About 12 miles of the Pernambuco Eailway 
are entirely laid with creosoted sleepers, principally in 
white sand. In this description of ballast the half-round 
sleepers have suffered, since the opening of the first section 
of the line in 1858 up to 1866, a depreciation of not more 



DEY TtOT IN TIMBER. 139 

than 1 per cent., whilst the sqiiare-sawn sleepers have 
experienced a depreciation of not^ less than 50 per cent 
Had the latter been placed in wet cuttings with ballast re- 
tentive of moisture, no doubt the whole of them would have 
required to be renewed. Hence it is evident that fine open 
sand ballast, which allows a free drainage during the rains, 
is best adapted for the preservation of sleepers in the tropics : 
it has also been found to be the best in most countries. 

The number of testimonials given in favour of creosote 
is very large, and are from the most eminent engineers 
of all countries, in addition to which Mr. Bethell lias 
received several medals at international exhibitions. 
The English engineers include Messrs. Brunei, Gregory, 
Abernethy, Ure, Hemans, Hawkshaw, and Cudworth ; the 
French, MM. Molinos and Forestier ; the Dutch, Messrs. 
Waldorp, Freem, and Von Baumhauer ; and the Belgian, 
M. Crepin. The late Mr. Brunei expressly stated that, 
in his opinion, well creosoted timbers would be found in a 
sound and serviceable condition at the expiration of forty 
years. M. Forestier, French engineer of La Vendee de- 
partment, reporting to the juries of the French Exhibition 
of 1867, cites a number of experiments he has lately tried 
upon many pieces of creosoted and uncreosoted oak, elm, 
ash, Swedish, Norwegian, and Dantzic red fir, Norway 
white fir, plane, and poplar, and shows that in each case, 
except that of the poplar, the resistance of the wood both 
to bending and crushing weight was much increased by 
creosoting. 

Drs. Brando, Ure, and Letheby, also bear testimony to 
the efficacy of this mode of preserving timber. 



140 PREVENTION AND CURE OF 

Creosoting has been extensively employed upon all the 
principal railways in Great Britain. In England, upon 
the London and North Western, North Eastern, South 
Eastern, Great Western, &c. In Scotland, on the Cale- 
donian, Great Northern, &c. In Ireland, on the Great 
Southern and Western, Midland, &c. It has also been 
and is being employed in Belgium, Holland, France, 
Prussia, India, and America. 

Between the years 1838 and 1840, Sir William Burnett's 
(formerly Director-General of the Medical Department of 
the Navy) process was first made known to the public. 

This process consists of an injection of chloride of zinc 
into timber, in the proportion of about 1 lb. of the salt to 
about 9 or 10 gallons of water, forced into the wood 
under a pressure of 150 lb. per square inch. 

The late Professor Graham thus wTote of its efficiency : 
" After making several experiments on wood prepared by 
the solution of chloride of zinc for the purpose of preserva- 
tion, and having given the subject my best consideration, 
1 have come to the following conclusions : 

" The wood appears to be fully and deeply penetrated 
by the metallic salt. I have found it in the centre of a 
large prepared block. 

" The salt, although very soluble, does not leave the 
wood easily when exposed to the weather, or buried in 
dry or damp earth. It does not come to the surface of the 
wood like the crystallizable salts. I have no doubt, in- 
deed, that the greater part of the salts will remain in the 
wood for years, when employed for railway sleepers or 
such purposes. This may be of material consequence 



DRY ROT IN TIMBER. 141 

when the wood is exposed to the attacks of insects, such 
as the white ant in India, which, I believe, would be re- 
pelled by the poisonous metallic salt. After being long 
macerated in cold water, or even boiled in water, thin chips 
of the prepared wood retain a sensible quantity of the 
oxide of zinc ; which I confirmed by Air. Toplis' test, and 
observed that the wood can be permanently dyed from 
being charged with a metallic mordant. 

"I have no doubt, from repeated observations made 
during several years, of the valuable preservative qualities 
of the solution of chloride of zinc, as applied in Sir W. 
Burnett's process; and would refer its beneficial action 
chiefly to the small quantity of the metallic salt, which 
is permanently retained by the ligneous fibre in all cir- 
cumstances of exposure. The oxide of zinc appears to 
alter and harden the fibre of the wood, and destroy the 
solubility, and prevent the tendency to decomposition 
of the azotised principles it contains by entering into 
chemical combination with them." 

The Eeport of the Jury, which was drawn up by the 
Count of Westphalia, at the Cologne International Agri- 
cultural Exhibition, in 1865, upon prepared specimens of 
timber, has the following remarks on the chloride of zinc 
process : 

1st. That chloride of zinc is the only substance which 

thoroughly penetrates the timber, and is at the 

same time the best adapted for its preservation. 
2nd. That the process of impregnating the wood after 

cutting is more useful and rational than doing so 

while the tree is growing. 



142 PREVENTION AND CURE OF 

3rd. That red beech is the only wood which has 
been impregnated in an uniform and thorough 
manner. 

It should, however, be stated that the Jury had very 
slender evidence presented to it respecting the creo- 
soting process. The creosoted specimens had been im- 
pregnated under the pressure of 60 lb. to 65 lb. per 
square inch for three or four hours, and were consequently 
inefficiently done ; in England the pressure per square 
inch would have been at least 140 lb. 

Drs. Brande and Cooper, of England, and Dr. Cleg- 
horn, of India, also wrote favourably of Sir W. Burnett's 
process. 

In 1847 a powerful cylinder, of Burnett's construction, 
hermetically closed, was laid down adjoining the sawmills 
in Woolwich dockyard. It was found to admit the 
largest description of timber for the purpose of having 
the moisture extracted, and the pores filled with chloride 
of zinc. Three specimens of wood — English oak, English 
elm, and Dantzic fir — remained uninjured in the fungus 
pit at Woolwich for five years ; while similar, but unpre- 
pared, specimens were all found more or less decayed. 

The cost of preparing timber by this process is 12s. per 
load, besides 2s. for landing and loading : 1 lb. of the 
material costing Is., which is sufficient for 9 or 10 gallons 
of water. 

Sir W. Burnett and Co.'s works for hydraulic apparatus 
and tanks are at Nelson Wharf, Mill wall, Poplar; their 
office is at 90, Cannon Street, London. Their terms 
are — 



DRY ROT IN TIMBER. 143 

" For timber, round or square, including planks, deals, hop-poles, paving- 
blocks, &c., against rot, 126-. per load of 50 cubic feet. 

" For park palings, cabinet work, wine and other laths, as per agree- 
ment. 

" For railway sleepers, 9 feet long, 10 inches by 5 inches, landing and 
reshipping included, 7c?. each. 

" For timber to be rendered uninflammable, 25s. per load." 

Sir W. Burnett's firm now sell their patent concentrated 
solution at 5s. per gallon: each gallon must be diluted 
with 40 gallons of water, according to the instructions in 
the licence, for which no charge is made. 

The reader will probably have observed that this process 
is considered to render timber uninflammable ; then let us 
see what will be the cost of obtaining a fire-proof house. 

The principal building material which causes the de- 
struction of our houses by fire is wood — comhustihle tvood. 
If, therefore, (as nearly all our houses are "brick and 
timber" erections,) we render this wood uninflammable, 
what will the cost be ? 

The following is an aj^proximate estimate of the extra 
expense, including sundries, &c. : — 



Timber and Deals. 
Loads. 

25 


Cost of House. 
£ 

1000 


Additional expense. 
£ 

34 


15 


600 


21 


10 


400 


14 


8 


250 


12 



When will the Building Act compel us to use this table 
in daily loractice ? 

xllthough among the many attempts to preserve wood 
those in England have proved the most successful, it 
should be mentioned that France, Germany, and America 
have given much attention to the subject. 



144 PREVENTION AND CURE OF 

At the end of the last century Du Hamel and Buffon 
pointed out the possibility of preserving wood, as well as 
the means of rendering it unalterable. As early as 1758 
Du Hamel made experiments on the vital suction of 
plants, and made some curious observations on the dif- 
ferent rings of vegetable matter which absorb most liquid 
in different plants. He also tried the effect of vital suction 
and pressure (of gravitation) acting at the same time. 
His process was reviewed by Barral in 1842. 

About 1784 M. Migneron invented a process about 
which little is now known, but the wood was covered with 
certain fatty substances. Wood nine years exposed to 
deterioration was improved by this process. M. Migneron 
had the approval of Fniffon, Franklin, and the Academies. 
His invention was again brought into notice in 1807, when 
it was found that timber which had been prepared by it in 
1784, and exposed more than twenty years, was quite sound. 

In 1811 Cadet de Gassicourt made different kinds of 
wood imbibe vegetable and mineral substances, and certain 
unguents : he used metallic salts (iron, tin, &c.). 

In 1813 M. Champy plunged wood into a bath of tallotv 
at 334^, and kept it there two or three hours. His experi- 
ments were afterwards repeated by Mr. Payne. 

About the year 1832 it was proposed in America to 
apply pyroligneous acid to the surface of wood, or intro- 
duce it by fumigation. 

Biot (who has written an excellent life of Sir Isaac 
Newton) remarked, in 1831, that wood could be soaked 
by pressure ; but his process of penetrating it with liquids 
was imperfect, and his discovery remains unapplied. 



DRY ROT IN TIMBER. 145 

A Frenchman, of the name of Breant, made about this 
time a discovery which preceded Boucherie's method, 
which is adopted to a great extent in France. Breant's 
apparatus consisted of a very ingenious machine, which, 
acting by pressure, caused liquids to penetrate to all points 
of a mass of wood of great diameter and considerable 
length. He may therefore be regarded as having solved 
the problem of penetration in a scientific, though not in 
a practically applied, point of view. Dr. Boucherie testi- 
fied before the Academic des Sciences, in 1840, to the 
merit of Breant's invention, which, with modifications by 
Payne, Brochard, and Gemini, has been worked in France 
and England. This process was recommended by Payne 
in 1840 and 1844, and imitated by him in France, and 
later on by Vengat and Bauner, who used both an air 
pump and a forcing pump. Breant obtained three patents, 
viz. 1st, in 1831, to act by pressure; 2nd, in 1837, by 
vital suction: and 3rd, in 1838, vacuum by steam. A 
mixture of linseed oil and resin succeeded best with him. 
He attached more importance to the thorough penetration 
of the wood than to the choice of the penetrating sub- 
stances. He borrowed his process from Du Hamel, but 
to make the necessary suction in the pores he produces a 
partial vacuum in the impregnating cylinder by filling it 
with steam, and condensing the steam. 

Previous to Boucherie's method, a German, Frantz 
Moll, in 1835, proposed to introduce into wood creosote 
in a state of vapour, but the process was found to be too 
expensive. This was a modification of Maconochie and 
Lukin's trials in 1805 and 1811.* A similar process has 
* See * Repertory of Patent Inventions/ December, 183G. 

L 



146 PREVENTION AND CURE OF 

since arisen in New York : we believe Mr. Eenwick, of 
that place, suggested it. 

Such were the known labours when Dr. Boucherie, 
in December, 1837, devoted his time to a series of ex- 
periments upon timber, with a view to discover some 
preservative process which should answer the following 
requirements : First, for protecting wood from dry rot or 
wet rot; second, for increasing its hardness; third, for 
preserving and developing its flexibility and elasticity; 
fourth, for preventing its decay, and the fissures that 
result from it, when, after having been used in construc- 
tion, it is left exposed to the variations of the atmosphere ; 
fifth, for giving it various and enduring colours and 
odours; and sixth and last, for greatly reducing its in- 
flammability. 

It is a curious coincidence that at Bordeaux, in 1733, 
the Academy received a memoir relative to the circulation 
of the sap and coloured liquids in plants ; and it was at 
Bordeaux, a century afterwards, viz. 1837, that M. Bou- 
cherie first mentioned his method. 

M. Boucherie's process was first discussed in Paris in 
June, 1840. It consists in causing a solution of sulphate 
of co;pper to penetrate to the interior of freshly cut woods, 
to preserve them from decay; he occasionally used the 
chloride of calcium, the pyrolignite of iron {pyrolignite 
Irut de fer), prussiate of iron, prussiate of copper, and 
various other metallic salts. As a general rule sulphate 
of copper is used; but Avhen the hardness of the wood 
is desired to be increased, pyrolignite of iron is taken 
(1 gallon of iron to 6 gallons of water) ; and when the 



DRY ROT IN TIMBER. 147 

object is to render the wood flexible, elastic, and at the 
same time uninflammable, chloride of calcium is used. 
The liquid is taken up by the tree either whilst growing 
in the earth or immediately after it has been felled. Not 
more than two or three months should be allowed to 
elapse before the timber is operated upon, but the s.ooner 
it undergoes the process after being felled the better. 

Sulphate of copper is said to be superior to corrosive 
sublimate. Dr. Boucherie's process of the injection of 
wood with the salts of copper is as simple as it is easy. 
For those woods intended for poles it consists in plunging 
the base of a branch, furnished with leaves, into a tub 
containing the solution. The liquid ascends into the 
branches by the action of the leaves, and the wood is 
impregnated with the preservative salt. As for logs, the 
operation consists in cutting down the tree to be operated 
upon ; fixing at its base a plank, which is fixed by means 
of a screw placed in the centre, and which can be 
tightened at will when placed in the centre of the tree. 
This plank has, on the side to be applied to the bottom of 
the tree, a rather thick shield of leather, cloth, pasteboard, 
or some other substance, intended to establish a space 
between it and the wood, sufficient for the preserving 
fluid to keep in contact with the freshly cut surface of 
the tree. The liquid is brought there from a tub or 
other reservoir, by the help of a slanting pole made 
on the upper surface of the tree, and in which is put a 
tube, adapted at its other extremity to a spigot in the 
upper reservoir which contains the solution. A pressufe 
of 5 metres suffices ; so that the instant the sap of the tree 

L 2 



148 PREVENTION AND CURE OF 

is drawn away it escapes, and is replaced by the liquid 
saturated with sulphate of copper. The proportion of 
sulphate of copper in the solution should be 1 lb. of the 
salt to 12^ gallons of water. As soon as the operation 
terminates (and it lasts for some hours for the most 
difficult logs), the wood is ready for use. 

For various practical reasons, the first invention of 
impregnating the wood of the tree whilst still in a 
growing state, causing it to suck up various solutions by 
means of the absorbing power of the leaves themselves, 
was subsequently abandoned ; and at the present time a 
cheap, simple, and effective process is adopted for im- 
pregnating the felled timbers with the preserving liquid, 
designated in France " trait de scie, et la cuisse foulante." 
The trunk of a newly felled tree is cut into a length 
suitable for two railway sleepers ; a cross cut is made on 
the prostrate timber to nearly nine-tenths of its diameter ; 
a wedge is then inserted, and a cord is w^ound round on 
the cut surface, leaving a shallow chamber in the centre, 
when it is then closed by withdrawing the wedge. A tube 
is then inserted through an auger hole into this chamber, 
and to this tube is attached an elastic connecting tube 
from a reservoir placed some 20 or 30 feet above the level 
on which the wood lies, and a stream of the saturating 
fluid with this pressure passes into the chamber, presses 
on the sap in the sap tubes, expels it at each end of the 
tree, and itself supplies its place. The fluid used is a 
solution of copper in water, in the proportion of 10 or 
12 per cent., and a chemical test that ascertains the 
pressure of the copper solution is applied at each end of 



DRY ROT IN TIMBER. 149 

the tree from which the sap exudes, by which the operator 
ascertains when the process is completed. 

A full account of this process may be found in the 
number for June, 1840, of * Les Annales de Chimie et de 
Physique.' Messrs. de Mirbel, Arago, Poucelet, Andouin, 
Gambey, Boussingault, and Dumas, on the part of FAca- 
demie des Sciences, made a report upon Dr. Boucherie's 
process, confirming the value of the invention. In France, 
Dr. Boucherie, some years since, relinquished his brevet, 
and threw the process open to the public, in consideration 
of a national reward ; whilst in England he has obtained 
two patents (1838 and 1841), wliich, however, are similar 
to Bethell's patent, obtained by him on July 11, 1838 : 
whicli is the same day and year of Boiceherie's patent. 
A prize medal was awarded for Dr. Boucherie's process at 
the Great Exhibition in London, in 1851, and a grande 
medaille d'honneur, at the Paris Exhibition of 1855. 
Many thousands of railway sleepers have been prepared 
by this process, and laid down on the Great Northern 
Railway of France, and are at present perfectly sound, 
whilst others not prepared, on the same line, have rotted. 
Boucherie's process was used on Belgium railways up to 
1859 ; and it is to be regretted that the reasons which led 
to its abandonment have not been given in the reports of 
the railway administration, as such reasons would have af- 
forded reliable data for future experimentalists to go upon. 

Messrs. Lege and Fleury - Pironnet's patent for the 
injection of sulphate of copper into beech and poplar is 
as follows: After the wood is placed, and the opening 
hermetically sealed, a jet of steam is introduced, intended 



150 PREVENTION AND CURE OF 

at first to enter the timber and open its pores for the 
purpose of obtaining a sudden vacuum, so as to establish 
at any time a communication between the interior of the 
cylinder and the cold water condenser ; at the same time 
the air pump is put in action. The vacuum caused is 
very powerful, and is equal to 25| ins. of the barometer. 
Under the double influence of the heat and the vacuum 
the sap is quickly evaporated from the wood as steam, 
and ejected from the cylinder by the air pump, so that in 
a very short time the wood is fully prepared to admit the 
preserving liquid through the entire bulk. 

The use of sulphate of copper for preserving timber 
has not been^ however, confined to France, for about the 
time Dr. Boucherie brought forward his process, a Mr. 
Margary took out a patent in England for the use of the 
same material. His method consists in steeping the sub- 
stances to be preserved in a solution of sulphate of copper, 
of the strength of 1 lb. of the sulphate to 8 gallons of 
water, and leaving them in it till thoroughly saturated. 
The timber is allowed to remain in the tank two days for 
every inch of its thickness. Another method is to place 
the timber in a closed iron vessel of great strength, and it 
is made to imbibe the solution by exhaustion and pres- 
sure, the operation occupying but a short time. 

Sulphate of copper is sold in quantities at 4d per lb. ; 
so that lOOZ. would buy 6000 lb., and each pound weight 
is sufficient for 7 or 8 gallons of water, according to Mar- 
gary ; or 12 gallons of water, according to Boucherie. 

To preserve railway sleepers, the French railway engi- 
neers require J lb. of sulphate of copper per cubic foot. 



DRY ROT IN TIMBER. 151 

say at least 12 lbs. to the load of 50 feet, to be used in a 
2 per cent, solution ; so that a load of timber can be ren- 
dered imperishable for the sum of four shillings, exclusive 
of labour, if sulphate of copper be reckoned at 4cZ. per lb. 

With respect to the use of pyrolignite of iron, Mr, 
Bethell considers it an expensive process, the pyrolignite 
costing 6d, to 9d. per gallon, whilst the oil of tar can be 
delivered at from 2d. to Sd. per gallon : the cost of these 
materials is constantly varying. 

A great many sleepers were prepared on the Great 
Western Eailway by pyrolignite of iron, and all have 
decayed. Their black colour makes them exactly resemble 
creosoted sleepers, and many mistakes have arisen from 
this resemblance. 

Messrs. Dorsett and Blythe's (of Bordeaux) patent pro- 
cess of preparing wood by the injection of heated solutions 
of sulphate of copper is said to have been adopted by 
French, Spanish, and Italian, as well as other continental 
railway companies, by the French Government for their 
navy and other constructions, and by telegraph companies 
for poles on continental lines. It is as cheap as creosote, 
and is employed in places where creosote cannot be had. 
Wood prepared by it is rendered incombustible. Wood 
for outdoor purposes so prepared has a clean yellowish 
surface, without odour; it requires no painting, remains 
unchangeable for any length of time, and can be employed 
for any purpose, the same as unprepared material, and 
carried with other cargo without hindrance.* Messrs. 

* See * Etuves de Desiccation ct Appareil pour rinjection des Bois.' 
Par MM. Dorsett et Blythe', manufacturiers, a Bordeaux. 1859. 



152 PREVENTION AND CURE OF 

Dorsett and Blythe's process is similar to that of Mr, 
Knab, which consisted of a solution of sulphate of copper, 
heated to nearly boiling point, and placed in a lead 
cylinder, protected by wood. 

In 1846, 80,000 sleepers, treated with sulphate of 
copper, were laid down on French railways, and after 
nine years' exposure were found to be as perfect as when 
first laid. 

y Mr. H. W. Lewis, University of Michigan, U. S., thus 
writes in the ' Journal ' of the Franklin Institute, in 1866, 
with reference to the decay of American railway sleepers : 
"Allowing 2112 sleepers per mile, at 50 cents each, 
1056 dols. per mile of American railroad decay every 
seven years. Thoroughly impregnate those sleepers with 
sulphate of copper, at a cost of 5 cents each, and they 
would last twice as long. Thus would be effected a saviug 
of 880 dols. per mile in the seven years on sleepers alone. 
In the United States, there are 33,906 ' 6 miles of railroad. 
The whole saving on these lines would be 29,389,568 dols., 

^ or upwards of 4,262,795 dols. per annum." 

With reference to the decay of unprepared wooden 
sleepers, it may be here stated that the renewal of wooden 
sleepers on the Calcutta and Delhi Indian line alone costs 
annually 130,000?. 

The preservative action of sulphate of copper on wood 
has long been known, but there are several things in its 
action which require explanation. The ^ London Keview ' 
says that Koenig has lately investigated the chemical 
reactions which occur when wood is impregnated with a 
preservative solution of blue vitriol. He finds, as a general 



DRY ROT IN TIMBER. 153 

rule, that a certain quantity of basic sulphate of copper 
remains combined in the pores of the wood in such a 
manner that it cannot be washed out with water. The 
copper salt may be seen by its green colour in the spaces 
between the yearly rings in the less compact portions of 
the wood, that is to say, in those portions which contain 
the sap. Those varieties of wood which contain the most 
resin retain the largest amount of the copper salt — oak, 
for example, retaining but little of it. The ligneous fibre 
itself appears to have little or nothing to do with the 
fluxation of the copper salt, and indeed none whatever is 
retained in chemical combination, so that it cannot be 
washed out with water, by pure cellulose. When wood, 
from which all resin has been extracted by boiling alcohol, 
is impregnated with sulphate of copper, it does not become 
coloured like the original resinous wood, and the copper 
salt contained in it may be readily washed out with water. 
In like manner, from impregnated resinous wood all the 
copper salt may be removed, with the resin, by means of 
alcohol. The constituents of the blue vitriol are con- 
sequently fixed in the wood by means of the resin w^hich 
this contains. Further, it is found that the impregnated 
wood contains less nitrogen than that which is unim- 
pregnated, and that it is even possible to remove all the 
nitrogenous components of the wood by long-continued 
treatment with the solution of sulphate of copper; the 
nitrogenous matters being soluble in an excess of this 
solution, just as the precipitate which forms when aqueous 
solutions of albumen and sulphate of copper are mixed is 
soluble in excess of the latter. Since the nitrogenous 



154 PKEYENTION AND CURE OF 

matters are well known to be promoters of putrefaction, 
their removal readily accounts for the increased durability 
of the impregnated wood. The utility of blue vitriol as a 
preservative may also depend on a measure upon the 
resinous copper salt which is formed, by which the pores 
of the wood are more or less filled up, and the ligneous 
fibre covered, so that contact with the air is prevented, 
and the attack of insects hindered. It is suggested that 
those cases in which the anticipated benefits have not 
been realized in practice, by impregnating wood with a 
solution of blue vitriol, may probably be referred to the 
use of an insufficient amount of this agent ; that is, where 
the wood was not immersed in the solution for a sufficient 
length of time. The action should be one of lixiviation, 
not merely of absorption. 

In 1841, a German, named Miienzing, a chemist of 
Heibronn, proposed chloride of manganese (waste liquor 
in the manufacture of bleaching powder) as a preservative 
against dry rot in timber ; but his process has not been 
adopted in England, and very little noticed abroad. 

In July, 1841, Mr. Payne patented his invention for 
sulphate of iron in London ; and in June and November, 
1846, in France ; and in 1846 in London, for carhonate of 
soda* The materials employed in Payne's process are 
sulphate of iron and sulphate of lime, both being held 
in solution with water. The timber is placed in a cylinder 
in w^hich a vacuum is formed by the condensation of 
steam, assisted by air pumps ; a solution of sulphate of 
iron is then admitted into the vessel, which instantly 
* See ' Kepertory of Patent Inventions,' April, 1847. 



DRY ROT IN TIMBER. 155 

insinuates itself into all the pores of the wood, previously 
freed from air by the vacuum, and, after about a minute's 
exposure, impregnates its entire substance ; the sulphate 
of iron is then withdrawn, and another solution of sidphate 
of lime thrown in, which enters the substance of the wood 
in the same manner as the former solution, and the two 
salts react upon each other, and form two new combina- 
tions within the substance of the wood — muriate of iron, 
and muriate of lime. One of the most valuable properties 
of timber thus prepared is its perfect incombustibility : 
when exposed to the action of flame or strong heat, it 
simply smoulders, and emits no flame. We may also 
reasonably infer that with such a compound in its pores, 
decay must be greatly retarded, and the liability to 
worms lessened, if not prevented. The greatest draw- 
back consists in the increased difficulty of working. 
This invention has been approved by the Commissioners 
of Woods and Forests, and has received much approbation 
from the architectural profession. Mr. Hawkshaw, C.E., 
considers that this^ process renders wood brittle. It was 
employed for rendering wood uninflammable in the 
Houses of Parliament (we presume, in the carcase ; for 
steaming was used for the joiner's work), British Museum, 
and other public buildings ; and also for the Eoyal Stables 
at Claremont. 

In 1842, Mr. Bethell stated before the Institute of 
Civil Engineers, London, that silicate of potash, or soluble 
glass, rendered wood uninflammable. 

In 1842, Professor Brande proposed corrosive sublimate 
in turpentine, or oil of tar, as a preservative solution. 



156 PREVENTION AND CURE OF 

In 1845, Mr. Kansome suggested the application of 
silicate of soda, to be afterwards decomposed by an acid 
in the fibre of tlie wood ; and in 1846, Mr Payne proposed 
soluble sulphides of the earth (barium sulphide, &c.), 
to be also afterwards decomposed in the woods by 
acids. 

In 1855, a writer in the ' Builder ' suggested an equal 
mixture of alum and borax (biborate of soda) to be used 
for making wood uninflammable. We have no objection 
to the use of alum and borax to render wood uninflam- 
mable, providing it does not hurt the wood. 

Such are the principal patents, suggestions, and in- 
ventions, up to the year 1856 ; but there are many more 
w^hich have been brought before the public, some of 
which we will now describe. 

Dr. Darwin, some years since, proposed absorption, first, 
of lime water, then of a weak solution of sulphuric acid, 
drying between the two, so as to form a gypsum (sulphate 
of lime) in the pores of the wood, the latter to be pre- 
viously well seasoned, and when prepared to be used in a 
dry situation. 

Dr. Parry has recommended a preparation composed of 
heeS'ivax, roll brimstone, and oil, in the proportion of 1, 
2, and 3 ounces to J gallon of water ; to be boiled together 
and laid on hot. 

Mr. Pritchard, C.E., of Shoreham, succeeded in esta- 
blishing pyrolignite of iron and oil of tar as a preventive 
of dry rot ; the pyrolignite to be used very pure, the oil 
applied afterwards, and to be perfectly free from any 
particle of ammonia. 



DBY ROT IN TIMBER. 157 

Mr. Toplis recommends the introduction into the pores 
of the timber of a solution of sulpliate or muriate of iron ; 
the solution may be in the proportion of about 2 lb. of 
the salt to 4 or 5 gallons of water. 

An invention has been lately patented by Mr. John 
Cullen, of the North London Eailway, Bow, for preserving 
wood from decay. The inventor proposes to use a com- 
position of coal-tar, lime, and charcoal; the charcoal to 
be reduced to a fine powder, and also the lime. These 
materials to be well mixed, and subjected to heat, and the 
wood immersed therein. The impregnation of the wood 
with the composition may be materially aided by means 
of exhaustion and pressure. Wood thus prepared is con- 
sidered to be proof against the attacks of the white ant. 

The process of preserving wood from decay invented by 
Mr. L. S. Eobins, of New York, was proposed to be worked 
extensively by the ^'British Patent Wood Preserving- 
Company." It consists in first removing the surface 
moisture, and then charging and saturating the wood with 
hot oleaginous vapours and compounds. As the Eobins' 
process applies the preserving material in the form of 
vapour, the wood is left clean, and after a few hours' 
exposure to the air it is said to be fit to be handled for 
any purposes in which elegant workmanship is required. 
Neither science nor extraordinary skill is required in con- 
ducting the process, and the treatment under the patent 
is said to involve only a trifling expense. 

Eeference has already been made to tlie use of petroleum. 
The almost unlimited supply of it within the last few years 
has opened out a new and almost boundless source of 



158 PREVENTION AND CURE OF 

wealth. An invention has been patented in the name of 
Mr. A. Prince, which purports to be an improvement in 
the mode of preserving timber by the aid of petroleum. 
The invention consists, firstly, in the immersion of the 
timber in a suitable vessel or receptacle, and to exhaust 
the air therefrom, by the ordinary means of preserving 
wood by saturation. The crude petroleum is next con- 
veyed into the vessel, and thereby caused to penetrate 
into every pore or interstice of the woody fibre, the effect 
being, it is said, to thoroughly preserve the wood from 
decay. He also proposes to mix any cheap mineral paint 
or pigment with crude petroleum to be used as a coating 
for the bottom of ships before the application of the sheath- 
ing, and also to all timber for building or other purposes. 
The composition is considered to render the timber inde- 
structible, and to repel the attacks of insects. Without 
expressing any opinion upon this patent as applied to wood 
for building purposes, we must again draw attention to 
the high inflammability of petroleum. 

The ' Journal' of the Board of Arts and Manufactures for 
Upper Canada considers the following to be the cheapest 
and the best mode of preserving timber in Canada : Let 
the timbers be placed in a drying chamber for a few hours, 
where they would be exposed to a temperature of about 
200^, so as to drive out all moisture, and by heat, coagu- 
late the albuminous substance, which is so productive of 
decay. Immediately upon being taken out of the drying 
chamber, they should be thrown into a tank containing 
crude petroleum. As the wood cools, the air in the pores 
will contract, and the petroleum occupy the place it filled. 



DRY ROT IN TIMBER. 159 

Such is the extraordinary attraction shown by this sub- 
stance for dry surfaces, that by the process called capillary 
attraction, it would gradually find its way into the interior 
of the largest pieces of timber, and effectually coat the 
walls and cells, and interstitial spaces. During the lapse 
of time, the petroleum would absorb oxygen, and become 
inspissated, and finally converted into a bituminous sub- 
stance, which would effectually shield the wood from de- 
struction by the ordinary processes of decay. The process 
commends itself on account of its cheapness. A drying 
chamber might easily be constructed of sheet iron properly 
strengthened, and petroleum is very abundant and acces- 
sible. Immediately after the pieces of timber have been 
taken out of the petroleum vat, they should be sprinkled 
with wood ashes in order that a coating of this substance 
may adhere to the surface, and carbonate of potash be 
absorbed to a small depth. The object of this is to render 
the surface incombustible; and dusting with wood ashes 
until quite dry will destroy this property to a certain extent. 
The woodwork of farm buildings in this country is some- 
times subjected to the following : Take two parts of gas-tar, 
one part of pitch, one part half caustic lime and half com- 
mon resin ; mix and boil these well together, afrtl put them 
on the wood quite hot. Apply two or three coats, and 
while the last coat is still warm, dash on it a quantity of 
well-washed sharp saud, previously prepared by being 
sifted through a sieve. The surface of the wood will then 
have a complete stone appearance, and may be durable. 
It is, of course, necessary, that the wood be perfectly dry, 
and one coat should be well hardened before the next is 



160 PREVENTION AND CURE OP 

put on. It is necessary, by the use of lime and long boil- 
ing, to get quit of the ammonia of the tar, as it is con- 
sidered to injure the wood. 

Mr. Abel, the eminent chemist to the War Department, 
recommends the application of silicate of soda in solution, 
for giving to wood, when applied to it like paint, a hard 
coating, which is durable for several years, and is also a 
considerable protection against fire. The silicate of soda, 
which is prepared for use in the form of a thick syrup, is 
diluted in water in the proportion of 1 part by measure 
of the syrup to 4 parts of water, which is added slowly, 
until a perfect mixture is obtained by constant stirring. 
The wood is then washed over two or three times with this 
liquid by means of an ordinary whitewash brush, so as to 
absorb as much of it as possible. When this first coating 
is nearly dry, the wood is painted over with another wash 
made by slaking good fat lime, diluted to the consistency 
of thick cream. Then, after the limewash has become 
moderately dry, another solution of the silicate of soda, in 
the proportion of 1 of soda to 2 of water, is applied in the 
same manner as the first coating. The preparation of 
the wood is then complete ; but if the lime coating has 
been applied too quickly, the surface of the wood may be 
found, when quite dry, after the last coating of the 
silicate, to give off a little lime when rubbed with the 
hand ; in which case it should be once more coated over 
with a solution of the silicate of the same strength as m 
the first operation. If Mr. Abel had been an architect 
or builder, he would never have invented this process. 
What would the cost be ? and would not a special clerk 



DRY ROT IN TIMBER. 161 

of the works be necessary to carry out this method in 
practice ? 

The following coating for piles and posts, to prevent 
them from rotting, has been recommended on account of 
its being economical, impermeable to w ater, and nearly as 
hard as stone : Take 50 parts of resin, 40 of finehj pow- 
dered chalk, 300 parts of fine white sharp sand, 4 parts of 
linseed oil, 1 part of native red oxide of copper, and 1 part 
of sulphuric acid. First, heat the resin, chalk, sand, and 
oil, in an iron boiler ; then add the oxide, and, with care, 
the acid ; stir the composition carefully, and apply the 
coat while it is still hot. If it be not liquid enough, add a 
little more oil. This coating, when it is cold and dry, 
forms a varnish which is as hard as stone. 

Another method for fencing, gate-posts, garden stakes, 
and timber which is to be buried in the earth, may be men- 
tioned. Take 11 lb. of hlue vitriol (sulphate of copper) 
and 20 quarts of water ; dissolve the vitriol with boiling 
water, and then add the remainder of the water. The 
end of the wood is then to be put into the solution, and 
left to stand four or five days; for shingle, three days 
will answer, and for posts, 6 inches square, ten days. 
Care should be taken that the saturation takes place in 
a well-pitched tank or keyed box, for the reason that 
any barrel will be shrunk by the operation so as to leak. 
Instead of expanding an old cask, as other liquids do, this 
shrinks it. This solution has also been used in dry rot 
cases, when the wood is only slightly affected. 

It will sometimes be found that when oak fencing is 
put up new, and tarred or painted, a fungus will vege- 

M 



162 PREVENTION AND CUBE OF 

tate tlirougli the dressing, and the interior of the wood 
be rapidly destroyed; but when undressed it seems 
that the weather desiccates the gum or sap, and leaves 
only the woody fibre, and the fence lasts for many 
years. 

About fifteen years ago, Professor Grace Calvert, F.E.S., 
made an investigation for the Admiralty, of the qualities 
of different woods used in ship-building. He found the 
goodness of teak to consist in the fact that it is highly 
charged with caoutchouc; and he considered that if the 
tannin be soaked out of a block of oak, it may then be 
interpenetrated by a solution of caoutchouc, and thereby 
rendered as lasting as teak. 

We can only spare the space for a few words about this 
method. 

1st. We have seen lead which has formed part of the 
gutter of a building previous to its being burnt down: 
lead melts at 612^ F. ; caoutchouc at 248^ F. ; therefore 
caoutchouc would not prevent wood from being destroyed 
by fire. At 248^ caoutchouc is highly inflammable, burns 
with a white flame and much smoke. 

2nd. We are informed by a surgical bandage-maker of 
high repute, that caoutchouc, when used in elastic knee- 
caps, &c., will perish y if the articles are left in a drawer 
for two or three years. When hard, caoutchouc is brittle. 

Would it be advisable to interpenetrate oak with a 
solution of caoutchouc ? In 1825, Mr. Hancock proposed 
a solution of 1^ lb. of caoutchouc in 3 lb. of essential 
oil, to which was to be added 9 lb. of tar. Mr. Parkes, 
in 1843, and M. Passez, in 1845, proposed to dissolve 



DRY ROT IN TIMBER. 163 

caoutchouc in sulphur: painting or immersing the wood. 
Maconochie, in 1805, after his return from India, proposed 
distilled teah chips to be injected into fir woods. 

Although England has been active in endeavouring to 
discover the best and cheapest remedy for dry rot, France 
has also been active in the same direction. 

M. le Comte de Chassloup Lambat, Member of the late 
Imperial Senate of France, considers that, as sulphur is 
most prejudicial to all species of fungi, there might, 
perhaps, be some means of making it serviceable in the 
preseryation of timber. We know with what success it is 
used in medicine. It is also known that coopers burn a 
sulphur match in old casks before using them — a practice 
which has evidently for its object the prevention of musti- 
ness, often microscopic, which would impart a bad flavour 
to the wine. 

M. de Lapparent, late Inspector-General of Timber for 
the French Navy, proposed to prevent the growth of fungi 
by the use of a paint having flour of sulphur as a basis, 
and linseed oil as an amalgamater. In 1862 he proposed 
charring wood ; we have referred to this process in our 
last chapter (p. 96). 

The paint was to be composed of : 

Flour of 8ulpl)ur 200 grammes 3,088 grains. 

Common linseed oil . . . . 135 „ 2,084 „ 

Prepared oil of manganese . . 30 „ 4G3 „ 

He considered that by smearing here and there either 
the surfaces of the ribs of a ship, or below the ceiling, 
with this paint, a slightly sulphurous atmosphere will 

M 2 



164 PBEVENTION AND CURE OF 

be developed in the hold, which will purify the air by- 
destroying, at least in part, the sporules of the fungi. He 
has since stated that his anticipations have been fully 
realized. M. de Lapparent also proposes to prevent the 
decay of timber by subjecting it to a skilful carbonization 
with common inflammable coal gas. An experiment was 
made at Cherbourg, which was stated to be completely 
successful. The cost is only about 10 cents per square 
yard of framing and planking.* M. de Lapparent's gas 
method is useful for burning off old paint. We saw it in 
practice (April, 1875) at Waterloo Eailway Station, Lon- 
don, and it appeared to be effective. 

At the suggestion of MM. Le Chatelier (Engineer-in- 
chief of mines) and Flachat, C.E.'s, M. Ranee, a few years 
since, injected in a Lege and Fleury cylinder certain 
pieces of white fir, red fir, and pitch pine with chloride 
of sodium^ which had been deprived of the manganesian 
salts it contained, to destroy its deliquescent property. 
Some pieces were injected four times, but the greatest 
amount of solution injected into pitch pine heartwood 
was from 3 to 4 per cent., and very little more was 
injected into the white and red fir heartwood. It was 
also noticed that sapwood, after being injected four times, 
only gained 8 per cent, in weight in the last three opera- 
tions. The experiments made to test the relative incom- 
bustibility of the injected wood showed that the process 
was a complete failure; the prepared wood burning as 
quickly as the unprepared wood. 

M. Paschal le Gros, of Paris, has patented his system for 
♦ See Chap. IV., p. 97. 



DRY ROT IN TIMBER. 165 

preserving all kinds of wood, by means of a doulle salt of 
manganese and of ziiic, used either alone or with an admix- 
ture of creosote. The solution, obtained in either of the tu o 
ways, is poured into a trough, and the immersion of the logs 
or pieces of wood is eiBfectedby placing them vertically in 
the trough in such a manner that they are steeped in the 
liquid to about three-quarters of their length. The wood 
is thus subjected to the action of the solution during a 
length of time varying from twelve to forty-eight hours. 
The solution rises in the fibres of the wood, and impreg- 
nates them by the capillary force alone, without requiring 
any mechanical action. The timber is said to become 
incombustible, hard, and very lasting. 

M. Fontenay, C.E., in 1832, proposed to act upon the 
wood with what he designated metallic soap, which could 
be obtained from the residue in greasing boxes of car- 
riages ; also from the acid remains of oil, suet, iron, and 
brass dust; all being melted together. In 1816 Chapman 
tried experiments with yellow soap ; but to render it suffi- 
ciently fluid it required forty times its weight of w^ater, 
in which the quantity of resinous matter and tallow 
would scarcely exceed ^Vth ; therefore no greater portion 
of these substances could be left in the pores of the wood, 
which could produce little effect. 

M. Letellier, in 1837, proposed to use deuto-chloride of 
mercury as a preservative for wood. 

M. Dondeine's process was formerly used in France and 
Germany. It is a paint, consisting of many ingredients, 
the principal being linseed oil, resin, ivhite lead, ver- 
milion, lard, and oxide of iron. All these are to be well 



166 PREVENTION AND CUBE OF 

mixed, and reduced by boiling to one-tenth, and then 
applied with a brush. If applied cold, a little varnish or 
turpentine to be added. 

Little is known in England of the inventions which 
have arisen in foreign countries not already mentioned. 

M. Szerelmey, a Hungarian, proposed, in 1868, potassa, 
lime, sulphurie acid, petroleum, &c., to preserve wood. 

In Germany, the following method is sometimes used for 
the preservation of wood : Mix 40 parts of ehalh, 40 parts 
of resin, 4 of linseed oil; melting them together in an iron 
pot ; then add 1 part of native oxide of copj^er, and after- 
wards, carefully, 1 part of sulphuric acid. The mixture is 
applied while hot to the wood by means of a brush, and it 
soon becomes very hard.* 

Mr. Cobley, of Meerholz, Hesse, has patented the fol- 
lowing preparation. A strong solution of potash, haryta, 
lime, strontia, or any of their salts, are forced into the 
pores of timber in a close iron vessel by a pump. After 
this operation, the liquid is run off from the timber, and 
hydrO'fluO'Silicic acid is forced in, which, uniting with the 
salts in the timber, forms an insoluble compound capable 
of rendering the wood uninflammable. 

About the year 1800, Neils Nystrom, chemist, Nor- 
kopping, recommended a solution of sea salt and copperas^ 
to be laid upon timber as hot as possible, to prevent 
rottenness or combustion. He also proposed a solution of 
sulphate of iron, potash, alum, &c., to extinguish fires. 

M. Louis Vernet, Buenos Ayres, proposed to preserve 
timber from fire by the use of the following mixture : Take 
* See coating for piles, p. 161. 



DRY ROT IN TIMBER. 167 

1 lb. of arsenic, 6 lb. of alum, and 10 lb. of jpotash, in 40 
gallons of water, and mix with oil, or any suitable tarry 
matters, and paint the timber with the solution. We 
have already referred to the conflicting evidence respect- 
ing alum and water for wood: we can now state that 
Chapman's experiments proved that arsenic afforded no 
protection against dry rot. Experiments in Cornwall 
have proved that where arsenical ores have lain on the 
ground, vegetation will ensue in two or three years after 
removal of the ore. If, therefore, alum or arsenic have 
no good effect on timber with respect to the dry rot, we 
think the use of both of them together would certainly be 
objectionable. 

The last we intend referring to is a composition fre- 
quently used in China, for preserving wood. Many 
buildings in the capital are painted with it. It is called 
Schoicao, and is made with 3 parts of blood deprived of 
its febrine, 4 parts of lime and a little alum, and 2 parts 
of liquid silicate of soda. It is sometimes used in Japan. 

It would be practically useless to quote any further 
remedies, and the reader is recommended to carefully 
study those quoted in this chapter, and of their utility 
to judge for himself, bearing in mind those principles 
which we have referred to before commencing to describe 
the patent processes. A large number of patents have 
been taken out in England for the preservation of wood 
by preservative processes, but only two are now in use, — 
that is, to any extent, — viz. Bethell's and Burnett's. ]\Iessrs. 
Bethell and Co. now impregnate timber with copper, zinc, 
corrosive suUimate, or creosote ; the four best patents. 



168 



PREVENTION AND CURE OF 



We insert here a short analy.'^is of different methods 
proposed for seasoning timber : — 



Vacnam and Pressure Processes 
generally. 

Breant's. 

Betbeirs. 

Payne's. 

Perm's. 

Tissier's. 



Vacuum by Condensation 
of Steam. 

Tissier. 

Breant. 

Payne. 

Renard Perm, 1848. 

Brocliard and Watteau, 1847. 



Separate Condenser. 
Tissier. 



Employ Sulphate of Copper in closed 
vessels. 

Betheirs Patent, IJth July, 1838. 

Tissier, 22nd October, 1844. 

Molin's Paper, 1853. 

Payen's Pamphlet. 

Lege and Fleury's Pamphlet. 



Current of Steam. 
Moll's Patent, 19th January, 1835. 
Tissier's „ 22nd October, 1844. 
Payne's „ 14th Nov., 1846. 
Meyer d'Uslaw, 2nd January, 1851. 
Payen's Pamphlet. 



Hot Solution. 
Tissier's Patent, 22nd October, 1844. 
Knab's Patent, 8th September, 1846. 

Most solutions used are heated. 



The following are the chief ingredients which have 
been recommended, and some of them tried, to prevent 
the decomposition of timber, and the growth of fungi : — 



Acid, Sulphuric. 


Salt, Selenites. 


„ Vitriolic. 


Oil, Veo^etable. 


„ of Tar. 


„ Animal. 


Carbonate of Potash. 


„ Mineral. 


>» 


Soda. 


Muriate of Soda. 


ij 


Barytes. 


Marcosites, Mundic. 


Sulphate 


of Copper. 


„ Barytes. 


>> 


Iron. 


Nitrate of Potash. 


)> 


Zinc. 


Animal Glue. 


91 


Lime. 


„ Wax. 


» 


Magnesia. 


Quick Lime, 


» 


Barytes. 


Resins of different kinds. 


» 


Alumina. 


Sublimate, Corrosive. 


V 


Soda. 


Peat Moss. 


Salt, Neutral. 





DRY ROT IN TIMBER. 169 

For the non-professional reader we find we have three 
facts : 

1st. The most snecessful patentees liave been Bethell 
and Biirnettj in England ; and Boncherie, in France : 
all B's. 

2nd. The most snecessful patents have been knighted, 
Payne's patent was, we believe, used by Sirs E. Smirke 
and C. Barry ; Kyan's, by Sir R. Smirke ; Burnett's, by 
Sirs M. Peto, P. Roney, and H. Dryden ; while BethelFs 
patent can claim Sir I. Brunei, and many other knights. 
We believe Dr. Boncherie received the Legion of Honour 
in France. 

3rd. There are only at the present time three timber- 
preserving works in London, and they are owned by 
Messrs. Bethell and Co., Sir F. Burnett and Co., and 
Messrs. Burt, Boulton, and Co. : all names commencing 
with the letter B. 

For the professional reader we find we have three hard 
facts : 

The most successful patents may be placed in three 
classes, and we give the key-note of their success. 

1st. One material and one application. — Creosote, 
Petroleum. Order — Ancient Egyptians, or Bethell's, 
Burmese. 

2nd. Two MATERIALS AND ONE APPLICATION. — Chloride 
of zinc and water ; sulphate of copper and water ; corro- 
sive sublimate and water. Order — Burnett, Bouclierie, 
Kyan. 

3rd. Two MATERIALS AND TWO APPLICATIONS. — Sul- 
phate of iron and water ; afterwards sulphate of lime and 
water. Payne. 



170 PREVENTION AND CUBE OF 

We thus observe there are twice three successful patent 
processes. 

Any inventions which cannot be brought under these 
three classes have had a short life ; at least, we think so. 

The same remarks will apply to external applications 
for wood — for instance, coal-tar, one a f plication, is more 
used for fencing than any other material. 

We are much in want of a valuable series of experi- 
ments on the application of various chemicals on wood to 
resist hurning to pieces; without causing it to rot speedily. 



DRY ROT IN TIMBER. 171 



CHAPTER YL 

ON THE MEANS OF PREVENTING DRY ROT IN MODERN 
HOUSES; AND THE CAUSES OF THEIR DECAY. 

Although writers on dry rot have generally deemed it a 
new disease, there is foundation to believe that it pervaded 
the British Navy in the reign of Charles II. " Dry rot 
received a little attention/' so writes Sir John Barrow, 
*' about the middle of the last century, at some period of 
Sir John Pringle's presidency of the Eoyal Society of 
London." As timber trees were, no doubt, subject to 
the same laws and conditions 500 years ago as they are 
at the present day, it is indeed extremely probable that 
if at that time unseasoned timber was used, and subjected 
to heat and moisture, dry rot made its appearance. We 
propose in this chapter to direct attention to the several 
causes of the decay of wood, which by proper building 
might be averted. 

The necessity of proper ventilation round the timbers of 
a building .has been repeatedly advised in this volume ; 
for even timber which has been naturally seasoned is at 
all times disposed to resume, from a warm and stagnant 
atmosphere, the elements of decay. We cannot there- 
fore agree with the following passage from Captain E. M. 
Shaw's book on *Fire Surveys,' which is to be found at 
page 44 : — '^ Circulation of air should on no account be 



172 PREVENTION AND CURE OF 

permitted in any part of a building not exposed to view, 
especially under floors, or inside skirting boards, or 
wainscots." In the course of this chapter, the evil results 
from a want of a proper circulation of air will be shown. 

In warm cellars, or any close confined situations, where 
the air is filled with vapour without a current to change 
it, dry rot proceeds with astonishing rapidity, and the 
timber work is destroyed in a very short time. The 
bread rooms of ships; behind the skirtings, and under 
the wooden floors, or the basement stories of houses, 
particularly in kitcliens, or other rooms where there are 
constant fires ; and, in general, in every place where wood 
is exposed to warmth and damp air, the dry rot will soon 
make its appearance. 

All kinds of stoves are sure to increase the disease if 
moisture be present. The eflTect of heat is also evident 
from the rapid decay of ships in hot climates; and the 
warm moisture given out by particular cargoes is also 
very destructive. Hemp will, without being injuriously 
heated, emit a moist warm vapour : so will pepper (which 
will affect teak) and cotton. The ship ' Brothers,' built at 
Whitby, of green timber, proceeded to St. Petersburgh 
for a cargo of hemp. The next year it was found on 
examination that her timbers were rotten, and all the 
planking, except a thin external skin. It is also an 
important fact that rats very rarely make their appear- 
ance in dry places : under floors they are sometimes very 
destructive. 

As rats will sometimes destroy the structural parts of 
wood framing, a few words about them may not be out of 



DRY ROT IN TIMBER. 173 

place. If poisoned wheat, arsenic, &c., be used, the 
creatures will simply eat the things and die under the 
floor, causing an intolerable stench. The best metliod is 
to make a small hole in a corner of the floor (unless they 
make it themselves) large enough to permit them to come 
up; the following course is then recommended: — Take 
oil of amber and ox-gall in equal parts ; add to them oat- 
meal or flour sufficient to form a paste, which divide into 
little balls, and lay them in the middle of the infested 
apartment at night time. Surround the balls with a 
number of saucers filled with water — the smell of the oil 
is sure to attract the rats, they will greedily devour the 
balls, and becoming intolerably thirsty will drink till they 
die on the spot. They can be buried in the morning. 

Building timber into new walls is often a cause of 
decay, as the lime and damp brickwork are active agents 
in producing putrefaction, particularly where the scrapings 
of roads are used, instead of sand, for mortar. Hence it is 
that bond timbers, wall plates, and the ends of girders, 
joists, and lintels are so frequently found in a state of 
decay. The ends of brestsummers are sometimes cased in 
sheet lead, zinc, or firebrick, as being impervious to 
moisture. The old builders used to bed the ends of 
girders and joists in loam instead of mortar, as directed 
in the Act of Parliament, 19 Car. II. c. 3, for rebuilding 
the City of London. 

In Norway, all posts in contact with the earth are care- 
fully wrapped round with flakes of birch bark for a levy 
inches above and below the ground. 

Timber that is to lie in mortar — as, for instance, the 



174 PREVENTION AND CURE OF 

ends of joists, door sills and frames of doors and windows, 
and the ends of girders — if pargeted over with hot pitch, 
will, it is said, be preserved from the effects of the lime. 
In taking down, some years since, in France, some portion 
of the ancient Chateau of the Eoque d'Oudres, it was 
found that the extremities of the oak girders were per- 
fectly preserved, although these timbers were supposed to 
have been in their places for upwards of 600 years. The 
whole of these extremities buried in the walls were com- 
pletely wrapped round with plates of cork. When de- 
molishing an ancient Benedictine church at Bayonne, it 
was found that the whole of the fir girders were entirely 
worm eaten and rotten, with the exception, however, of 
the bearings, which, as in the case just mentioned, were 
also completely wrapped round with plates of cork. These 
facts deserve consideration. 

If any of our professional readers should wish to try 
cork for the ends of girders, they will do well to choose 
the Spanish cork, which is the best. 

In this place it may not be amiss to point out the 
dangerous consequences of building walls so that their 
principal support depends on timber. The usual method 
of putting bond timber into walls is to lay it next the 
inside ; this bond often decays, and, of course, leaves the 
walls resting only upon the external course or courses of 
brick ; and fractures, bulges, or absolute failures are the 
natural consequences. This evil is in some degree avoided 
by placing the bond in the middle of the wall, so that 
there is brickwork on each side, and by not putting con- 
tinued bond for nailing the battens to. We object to- 



DRY ROT IN TIMBER. 175 

placing bond in the middle of a wall : the best way, 
where it can be managed, is to corbel out the wall, resting 
the ends of the joists on the top course of bricks; thus 
doing away with the wood-plate. In London, wood bond is 
prohibited by Act of Parliament, and hoop-iron bond (well 
tarred and sanded) is now generally used. The following 
is an instance of the bad effects of placing wood bond in 
walls : In taking down portions of the audience part and 
the whole of the corridors of the original main walls of 
Covent Garden Theatre, London, in 1847, which had only 
been built about thirty-five years, the wood horizontal 
bond timbers, although externally appearing in good con- 
dition, were found, on a close examination by Mr. Albano, 
much affected by shrinkage, and the majority of them 
quite rotten in the centre, consequently the whole of them 
were ordered to be taken out in short lengths, and the 
space to be filled in with brickwork and cement. 

Some years since we had a great deal to do with ^' Fire 
Surveys ; " that is to say, surveying buildings to estimate 
the cost of reinstating them after being destroyed by fire ; 
and we often noticed that the wood bond, being rotten, 
was seriously charred by the fire, and had to be cut out 
in short lengths, and brickwork in cement '' pinned in " 
in its place. Brestsummers and story posts are rarely 
sufficiently burnt to affect the stability of the front wall 
of a shop building. 

In bad foundations, it used to be common, before con- 
crete came into vogue, to lie planks to build upon. Unless 
these planks were absolutely wet, they were certain to rot 
in such situations, and the walls settled ; and most likely 



176 PREVENTION AND CURE OP 

irregularly, rending the building to pieces. Instances of 
such kind of failure frequently occur. It was found neces- 
sary, a few years since, to underpin three of the large 
houses in Grosvenor Place, London, at an immense ex- 
pense. In one of these houses the floors were not less 
than three inches out of level, the planking had been 
seven inches thick, and most of it was completely rotten : 
it was of yellow fir. A like accident happened to Norfolk 
House, St. James's Square, London, where oak planking 
had been used. 

As an example of the danger of trusting to timber in 
supporting heavy stone or brickwork, the failure of the 
curb of the brick dome of the church of St. Mark, at 
Venice, may be cited. This dome was built upon a curb 
of larch timber, put together in thicknesses, with the joints 
crossed, and was intended to resist the tendency which a 
dome has to spread outwards at the base. In 1729, a 
large crack and several smaller ones were observed in the 
dome. On examination, the wooden curb was found to be 
in a completely rotten state, and it was necessary to raise 
a scaffold from the bottom to secure the dome from ruin. 
After it was secured from falling, the wooden curb was 
removed, and a course of stone, with a strong band of iron, 
was put in its place. 

It is said that another and very important source of 
destruction is the applying end to end of two different 
kinds of wood : oak to fir, oak to teak or lignum vitaB ; the 
harder of the two will decay at the point of juncture. 

The bad effects resulting from damp walls are still 
further increased by hasty finishing. To enclose with 



DRY KOT IN TIMBER. 177 

plastering and joiners^ work the walls and timbers of a 
building while they are in a damp state is the most 
certain means of causing the building to fall into a 
premature state of decay. 

Mr. George Baker, builder of the National Gallery, 
London, remarked, in 1835, "1 have seen the dry rot all 
over Baltic timber in three years, in consequence of 
putting it in contact with moist brickwork ; the rot was 
caused by the badness of the mortar, it was so long 
drying." 

Slating the external surface of a wall, to keep out the 
rain or damp, is sometimes adopted : a high wall (nearly 
facing the south-west) of a house near the north-west 
corner of Blackfriars Bridge, London, has been recently 
slated from top to bottom, to keep out damp. 

However well timber may be seasoned, if it be employed 
in a damp situation, decay is the certain consequence ; 
therefore it is most desirable that the neighbourhood of 
buildings should be well drained, which would not only 
prevent rot, but also increase materially the comfort of 
those who reside in them. The drains should be made 
water-tight wherever they come near to the walls; as 
walls, particularly brick walls, draw up moisture to a very 
considerable height: very strict supervision should be 
placed over workmen while the drains of a building are 
being laid. Earth should never be suffered to rest 
against walls, and the sunk stories of buildings should 
always be surrounded by an open area, so that the walls 
may not absorb moisture from the earth : even open 
areas require to be properly built. We will quote a case 

N 



178 . PREVENTION AND CURE OF 

to explain our meaning. A house was erected about 
eighteen months ago, in the south-east part of London, 
on sloping ground. Excavations were made for the base- 
ment floor, and a dry area, " brick thick, in cement," 
was built at the back and side of the house, the top of 
the area wall being covered with a stone coping ; we do 
not know whether the bottom of the area was drained. 
On the top of the coping was placed'mould, forming one 
of the garden beds for flowers. Where the mould rested 
against the walls, damp entered. The area walls should 
have been built, in the first instance, above the level of 
the garden-ground — which has since been done — other- 
wise, in course of time, the ends of the next floor joists 
would have become attacked by dry rot. 

Some people imagine that if damp is in a wall the best 
way to get rid of it is to seal it in, by plastering the 
inside and stuccoing the outside of the wall ; this is a great 
mistake ; damp will rise higher and higher, until it finds 
an outlet ; rotting in the meanwhile the wood bond and 
ends of all the joists. We were asked recently to 
advise in a curious case of this kind at a house in Croy- 
don. On wet days the wall (stucco, outside; plaster, 
inside) was perfectly wet : bands of soft red bricks in 
wall, at intervals, were the culprits. To prevent moisture 
rising from the foundations, some substance that will not 
allow it to pass should be used at a course or two above 
the footings of the walls, but it should be below the level 
of the lowest joists. " Taylor's damp course " bricks are 
good, providing the air-passages in them are kept free for 
air to pass through : they are allowed sometimes to get 



DRY KOT IN TIMBER, 179 

choked up with dirt. Sheets of lead or copper have been 
used for that purpose, but they are very expensive. 
Asphalted felt is quite as good ; no damp can pass 
through it. Care must, however, be taken in using it if 
only one wall, say a party wall, has to be built. To lay two 
or three courses of slates, bedded in cement, is a good 
method, providing the slates " break joint," and are well 
bedded in the cement. Workmen require watching while 
this is being done, because if any opening be left for damp 
to rise, it will undoubtedly do so. A better method is to 
build brickwork a few courses in height with Portland 
cement instead of common mortar, and upon the ^upper 
course to lay a bed of cement of about one inch in thick- 
ness ; or a layer of asphalte (providing the walls are all 
carried up to the same level before the asphalte is applied 
hot). As moisture does not penetrate these substances, 
they are excellent materials for keeping out wet ; and it 
can easily be seen if the mineral asphalte has been pro- 
perly applied. To keep out the damp from basement 
floors, lay down cement concrete 6 inches thick, and on 
the top, asphalte 1 inch thick, and then lay the sleepers 
and joists above ; or bed the floor boards on the asphalte. 
The walls and principal timbers of a building should 
always be left for some time to dry after it is covered in. 
This drying is of the greatest benefit to the work, particu- 
larly the drying of the walls ; and it also allows time for 
the timbers to get settled to their proper bearings, which 
prevents after-settlements and cracks in the finished 
plastering. It is sometimes said that it is useful because 
it allows the timber more time to season ; but when the 

N 2 



180 PKEVENTION AND CURE OF 

carpenter considers that it is from the ends of the timber 
that much of its moisture evaporates, he will see the im- 
propriety of leaving it to season after it is framed, and 
also the cause of framed timbers of unseasoned wood fail- 
ing at the joints sooner than in any other place. No parts 
of timber require the perfect extraction of the sap so 
much as those that are to be joined. 

When the plastering is finished, a considerable time 
should be allowed for the work to get dry again before 
the skirtings, the floors, and other joiners' work be fixed. 
Drying will be much accelerated by a free admission of 
air, particularly in favourable weather. When a building 
is thoroughly dried at first, openings for the admission of 
fresh air are not necessary when the ^precautions against 
any neiv accessions of moisture have leen effectual. Indeed, 
such openings only afford harbour for vermin : unfortu- 
nately, however, buildings are so rarely dried when first 
built, that air-bricks, &c., in the floors are very necessary, 
and if the timbers were so dried as to be free from water 
(which could be done by an artificial process), the wood 
would only be fit for joinery purposes. Few of our 
readers would imagine that water forms -|^th part of wood. 
Here is a table (compiled from ^ Box on Heat,' and Peclet's 
great work ' Traite de la Chaleur ') : — 

Wood. 

Elements. Ordinary state. 

Carbon , -408 

Hydrogen '042 

Oxygen -334 

Water 200 

Ashes -016 

1-000 



DRY ROT IN TIMBER. 181 

Many houses at our seaport towns are erected with 
mortar, having sea-sand in its composition, and then dry- 
rot makes its appearance. If no other sand can be 
obtained, the best way is to have it washed at least three 
times (the contractor being under strict supervision, and 
subject to heavy penalties for evasion). After each 
washing it should be left exposed to the action of the 
sun, wind, and rain : the sand should also be frequently 
turned over, so that the whole of it may in turn be 
exposed ; even then it tastes saltish, after the third opera- 
tion. A friend of ours has a house at Worthing, which 
was erected a few years since with sea-sand mortar, and 
on a wet day there is always a dampness hanging about 
the house — every third year the staircase walls have to 
be rej)apered : it ^^ bags " from the walls. 

In floors next the ground we cannot easily prevent the 
access of damp, but this should be guarded against as far 
as possible. All mould should be carefully removed, and, 
if the situation admits of it, a considerable thickness of 
dry materials, such as brickbats, dry ashes, broken glass, 
clean pebbles, concrete, or the refuse of vitriol-works ; but 
no lime (unless unslaked) should be laid under the floor, 
and over these a coat of smiths' ashes, or of pyrites, w^here 
they can be procured. The timber for the joists should 
be w^ell seasoned ; and it is advisable to cut off" all connec- 
tion between wooden ground floors and the rest of the 
woodwork of the building. A flue carried up in the wall 
next the kitchen chimney, commencing under the floor, 
and terminating at the top of the w^all, and covered to pre- 
vent the rain entering, would take away the damp under 



182 PKEVENTION AND CURE OF 

a kitchen floor. In Hamburg it is a common practice to 
apply mineral asphalte to the basement floors of houses 
to prevent capillary attraction ; and in the towns of the 
north of France, gas-tar has become of very general use 
to protect the basement of the houses from the effects 
of the external damp. 

Many houses in the suburbs (particularly Stucconia) of 
London are erected by speculating builders. As soon as 
the carcase of a house is finished (perhaps before) the 
builder is unable to proceed, for want of money, and the 
carcase is allowed to stand unfinished for months. Showers 
of rain saturate the previously unseasoned timbers, and 
pools of water collect on the basement ground^ into w hich 
they gradually, but surely, soak. Eventually the houses 
are finished (probably by half a dozen different tradesmen, 
employed by a mortgagee) ; bits of wood, rotten sawdust, 
shavings, &c., being left under the basement floor. The 
house when finished, having pretty (!) paper on the walls, 
plate-glass in the window-sashes, and a bran new brick 
and stucco portico to the front door, is quickly let. Dry 
rot soon appears, accompanied with its companions, the 
many-coloured fungi; and when their presence should 
be known from their smell, the anxious wife probably 
exclaims to her husband, '' My dear ! there is a very 
, strange smell which appears to come from the children's 
playroom: had you not better send for Mr. Wideawake, 
the builder, for I am sure there is something the matter 
with the drains^ Defective ventilation, dry rot, green 
water thrown down sinks, &c., do not cause smells, it's 
the drains^ of course ! 



DRY ROT IN TIMBER. 183 

There is another cause which affects all wood most 
materially, which is the application of paint, tar, or pitch 
before the wood has been thoroughly dried. The nature 
of these bodies prevents all evaporation ; and the result of 
this is that the centre of the wood is transformed into 
touchwood. On the other hand, the doors, pews, and 
carved work of many old churches have never been 
painted, and yet they are often found to be perfectly 
sound, after having existed more than a century. In 
Chester, Exeter, and other old cities, where much timber 
w^as formerly used, even for the external parts of build- 
ings, it appears to be sound and perfect, though black 
with age, and has never been painted. 

Mr. Semple, in his treatise on 'Building in Water,' 
mentions an instance of some field-gates made of home fir, 
part of which, being near the mansion, were painted ; while 
the rest, being in distant parts of the grounds, were not 
painted. Those" which were painted soon became quite 
rotten, but the others, which were not painted, continued 
sound. 

Another cause of dry rot, which is sometimes found in 
suburban and country houses, is the presence of large 
trees near the house. We are acquainted with the 
following remarkable instance : — At the northern end of 
Kilburn, London, stands Stanmore Cottage, erected a 
great many years ago : about fifty feet in front of it is an 
old elm-tree. The owner, a few years since, noticed 
cracks round the portico of the house; these cracks 
gradually increased in size, and other cracks appeared 
in the window arches, and in different parts of the ex- 



184 PREVENTION AND CURE OF 

ternal and internal walls. The owner became alarmed, 
and sent for an experienced builder, who advised under- 
pinning the walls. Workmen immediately commenced to 
remove the ground from the foundations, and it was then 
found that the foundations, as well as the joists, were 
honeycombed by the roots of the elm-tree, which were 
growing alongside the joists, the whole being surrounded 
by large masses of white and yellow dry-rot fungus. 

The insufficient use of tarpaulins is another frequent 
cause of dry rot. A London architect had (a few years 
since) to superintend the erection of a church in the 
south-west part of London; an experienced builder was 
employed. The materials were of the best description 
and quality. When the walls were sufficiently advanced 
to receive the roof, rain set in; as the clown in one of 
Shakespeare's plays observed, " the rain, it raineth every 
day ; " it was so, we are told, in this case for some days. 
The roof when finished was ceiled below with a plaster 
ceiling ; and above (not with '' dry oakum without pitch '' 
but) with slates. A few months afterwards some of the 
slates had to be reinstated, in consequence of a heavy 
storm, and it was then discovered that nearly all the 
timbers of the roof were affected by dry rot. This was 
an air-tight roof. 

In situations favourable to rot, painting prevents every 
degree of exhalation^ depriving at the same time the wood 
of the influence of the air, and the moisture runs through 
it, and insidiously destroys the wood. Most surveyors 
know that moist oak cills to window frames will soon rot, 
and the painting is frequently renewed ; a few taps with a 



DRY ROT IN TIMBER. 185 

two-feet brass rule joint on the top and front of cill will soon 
prove their condition. Wood should be a year or more 
before it is painted; or, better still, never painted at 
all. Artificers can tell by the sound of any substance 
whether it be healthy or decayed as accurately as a 
musician can distinguish his notes : thus, a bricklayer 
strikes the wall with his crow, and a carpenter a piece of 
timber with his hammer. The Austrians used formerly 
to try the goodness of the timber for shipbuilding by the 
following method: One person applies his ear to the 
centre of one end of the timber, while another, with a key, 
hits the other end with a gentle stroke. If the wood be 
sound and good, the stroke will be distinctly heard at the 
other end, though the timber should be fifty feet or more 
in length. Timber affected with rot yields a particular 
sound when struck, but if it were painted, and the dis- 
temper had made much progress, with no severe stroke 
the outside breaks like a shell. The auger is a very use- 
ful instrument for testing wood; the wood or saw- 
dust it brings out can be judged by its smell ; which 
may be the fresh smell of pure wood : the vinous smell, 
or first degree of fermentation, which is alcoholic ; or the 
second degree, which is putrid. The sawdust may also be 
tested by rubbing it between the fingers. 

According to Colonel Berrien, the Michigan Central 
Kailroad Bridge, at Niles, was painted lefore seasoning, 
with "Ohio fire-proof paint," forming a glazed surface. 
After five years it was so rotten as to require rebuilding. 

Painted floor-cloths are very injurious to wooden floors, 
and frequently produce rottenness in the floors that are 



186 PREVENTION AND CURE OF 

covered with them, as the painted cloth prevents the 
access of air, and retains whatever dampness the boards may 
absorb, and therefore soon causes decay. Carpets are not 
so injurious, but still assist in retarding free evaporation. 

Captain E. M. Shaw, in * Fire Surveys,' thus writes of 
the floors of a building, " They might with advantage be 
caulked like a ship's deck, only with dry oakum, without 
pitch." Let us see how far oil floor-cloth and kamptulicon 
will assist us in obtaining an air-tight floor. 

In London houses there is generally one room on the 
basement floor which is carefully covered over with an 
oiled floor-cloth. In such a room the dry rot often makes 
its appearance. The wood absorbs the aqueous vapour 
w^hich the oil-cloth will not allow to escape; and being 
assisted by the heat of the air in such apartments, the 
decay goes on rapidly. Sometimes, however, the dry rot 
is only confined to the top of the floor. At No. 106, Fen- 
church Street, London, a wood floor was washed (a few 
years since) for a tenant, and oil-cloth was laid down. 
Circumstances necessitated his removal a few months 
afterwards ; and it was then found that the oil-cloth had 
grown, so to speak, to the wood flooring, and had to be 
taken off with a chisel : the dry rot had been engendered 
merely on the surface of the floor boards, as they were 
sound below as well as the joists : air bricks were in the 
front wall. 

We have seen many instances of dry rot in passages, 
where oiled floorcloth has been nailed down and not been 
disturbed for two or three years. 

In ordinary houses, where floorcloth is laid down in the 



DKY ROT IN TIMBER. 187 

front kitchen, no ventilation under the floors, and a fire 
burning every day in the stove, dry rot often appears. 
In the hack kitchen, where there is no floorcloth, and only 
an occasional fire, it rarely appears. The air is warm and 
stagnant under one floor, and cold and stagnant under 
the other : at the temperature of 32"^ to 40° the progress 
of dry rot is very slow. 

And how does hamptulicon behave itself? The following 
instances of the rapid progress of dry rot from external 
circumstances have recently been communicated to us; 
they show^ that, under favourable circumstances as to 
choice of timber and seasoning, this fungus growth can 
be readily produced by casing-in the timber with sub- 
stances impervious, or nearly so, to air. 

At No. 29, Mincing Lane, London, in two out of three 
rooms on the first floor, upon a fire-proof floor constructed 
on the Fox and Barrett principle (of iron joists and 
concrete with yellow pine sleepers, on strips of wood 
bedded in cement, to which were nailed the yellow pine 
floor-boards) kamptulicon was nailed down by the tenant's 
orders. In less than nine months the whole of the wood 
sleepers, and strips of wood, as well as the boards, were 
seriously injured by dry rot ; whilst the third room floor, 
which had been covered with a carpet, was perfectly 
sound. 

At No. 79, Gracechurch Street, London, a room on the 
second floor was inhabited, as soon as finished, by a tenant 
who had kamptulicon laid down. This floor was formed 
in the ordinary way, with the usual sound boarding of 
strips of wood, and concrete two inches thick filled in on 



188 PREVENTION AND CURE OF 

the same, leaving a space of about two inches under the 
floor boards. The floor was seriously decayed by dry rot 
in a few months down to the level of the concrete pug- 
ging, below which it remained sound, and could be pulled 
up with the hand. 

We will now leave oil-cloth and kamptulicon, and try 
what " Keene's cement " will do for an " air-tight " par- 
tition of a house. 

At No. 16, Mark Lane, London, a partition was con- 
structed of sound yellow deal quarters, covered externally 
with "Keene's cement, on lath, both sides." It was 
removed about two years after its construction, when it 
was found that the timber was completely perished from 
dry rot; so much so, that the timbers parted in the middle 
in places, and were for some time afterwards moist. 

It is still unfortunately the custom to keep up the old 
absurd fashion of disguising woods, instead of revealing 
their natural beauties. Instead of wasting time in perfect 
imitations of scarce or dear woods, it would be much 
better to employ the same amount of time in fully de- 
veloping the natural characteristics of many of our native 
woods, now destined for decorative purposes because they 
are cheap and common ; although many of our very com- 
monest woods are very beautifully grained, but their ex- 
cellences for ornamentation are lost because our decorators 
have not studied the best mode of developing their 
beauties. Who would wish that stained deal should be 
painted in imitation of oak? or that the other materials 
of a less costly and inferior order should have been painted 
over instead of their natural faces being exposed to view ? 



DRY ROT IN TIMBER. 189 

There are beauties in all the materials used. The in- 
ferior serve to set off by comparison the more costly, and 
increase their effect. The red, yellow, and white veins of 
the pine timber are beautiful : the shavings are like silk 
ribbons, which only nature could vein after that fashion, 
and to imitate which would puzzle all the tajpissiers of the 
Rue Mouffetard, in Paris. 

Why should not light and dark woods be commonly used 
in combination with each other in our joinery ? Wood may 
be stained of various shades, from light to dark. The dirt 
or dust does not show more on stained wood than it does 
on paint, and can be as easily cleaned and refreshed by 
periodical coats of varnish. Those parts subjected to con- 
stant wear and tear can be protected by more durable 
materials, such as finger-plates, &c. Oak can be stained 
dark, almost black, by means of bichromate of potash 
diluted with water. Wash the wood over with a solution 
of gallic acid of any required strength, and allow it to 
thoroughly dry. To complete the process, wash with a 
solution of iron in the form of " tincture of steel," or a 
decoction of vinegar and iron filings, and a deep and good 
stain will be the result. If a positive black is required, 
wash the wood over with gallic acid and water two or 
three times, allowing it to dry between every coat ; the 
staining with the iron solution may be repeated. Raw 
linseed oil will stay the darker process at any stao-e. 

Doors made up of light deal, and varied in the stainin^ 
would look as well as the ordinary graining. Good and 
well-seasoned materials would have to be used, and the 
joiners' work well fitted and constructed. Mouldings of a 



190 PREVENTION AND CURE OF 

superior character, and in some cases gilt, might be used 
in the panels, &c. For doors, plain oak should be used for 
the stiles and rails, and pollard oak for the panels. If 
rose-wood or satin-wood be used, the straight-grained wood 
is the best adapted for stiles and rails ; and for mahogany 
doors, the lights and shades in the panels should be 
stronger than in the stiles and rails. 

Dark and durable woods might be used in parts most 
exposed to wear and tear. 

Treads of stairs might be framed with oak nosings, if 
not at first, at least when necessary to repair the nosings. 

Skirtings could be varied by using dark and hard woods 
for the lower part or plinth, lighter wood above, and 
finished with superior mouldings. It must, however, be 
remembered that, contrary to the rule that holds good 
with regard to most substances, the colours of the gene- 
rality of woods become considerably darker by exposure 
to the light ; allowance would therefore have to be made 
for this. All the woodwork must, previously to being- 
fixed, be well seasoned. 

The practice here recommended would be more expen- 
sive than the common method of painting, but in many 
cases it would be better than graining, and cheaper in the 
long run. Oak wainscot and Honduras mahogany doors 
are twice the price of deal doors; Spanish mahogany 
three times the price. When we consider that by using 
the natural woods, French polished, we save the cost of 
four coats of paint and graining (the customary modes), 
the difi'erence in price is very small. An extra 50Z. laid 
out on a 500?, house would give some rooms varnished 



DRY ROT IN TIMBER. 19 

and rubbed fittings, without paint. Would it not be 
worth the outlay ? It may be said that spots of grease 
and stains would soon disfigure the bare wood ; if so, they 
could easily be removed by the following process : Take 
a quarter of a pound of fuller's earth, and a quarter of a 
pound of pearlash, and boil them in a quart of soft water, 
and, while hot, lay the composition on the greased parts, 
allowing it to remain on them for ten or twelve hours ; 
after which it may be washed off with fine sand and water. 
If a floor be much spotted with grease, it should be com- 
pletely washed over with this mixture, and allowed to 
remain for twenty-four hours before it is removed. 

Let us consider how w^e paint our doors, cupboards, &c., 
at the present time. For our best houses, the stiles of our 
doors are painted French w^hite ; and the panels, pink, or 
salmon colour ! For cheaper houses, the doors, cupboards, 
window linings, &c., are generally two shades of what is 
called "stone colour" (as if stone ^vas always the same 
colour), and badly executed into the bargain: the best 
rooms having the woodwork grained in imitation of oak, 
or satin-wood, &c. And such imitations ! Mahogany and 
oak are now even imitated on leather and paper-hangings. 
Wood, well and cleanly varnished, stained, or, better still, 
French polished, must surely look better than these daubs. 
But French polish is not extensively used in England : it 
is confined to cabinet pieces and furniture, except in the 
houses of the aristocracy. Clean, colourless varnish ought 
to be more generally used to finish off our woodwork, 
instead of the painting now so common. The varnish 
should be clean and colourless, as the yellow colour of the 



192 PREVENTION AND CURE OF 

ordinary varnishes greatly interferes with the tints of the 
light woods. 

In the Imperial Palace, at Berlin, one or two of the 
Emperor's private rooms are entirely fitted up with deal 
fittings ; doors, windows, shutters, and everything else of 
fir-wood. '^ Common deal," if well selected, is beautiful? 
cheap, and pleasing. 

We have seen the offices of Herr Krauss (architect to 
Prince and Princess Louis of Hesse), who resides at 
Mayence, and they are fitted up, or rather the walls and 
ceilings are lined, with picked pitch pine-wood, parts 
being carved, and the whole French polished, and the 
effect is much superior to any paint, be it '' stone colour," 
*^ salmon colour," or even " French white." 

The reception-room, where the Emperor of Germany 
usually transacts business with his ministers, and receives 
deputations, &c., as well as the adjoining cabinets, are 
fitted with deal, not grained and painted, but well French 
polished. The wood is, of course, carefully selected, care- 
fully wrought, and excellently French polished, which is 
the great secret of the business. In France, it is a very 
common practice to polish and wax floors. 

The late Sir Anthony Carlisle had the interior wood- 
work of his house, in Langham Place, London, varnished 
throughout, and the effect of the varnished deal was very 
like satin-wood. 

About forty years since, Mr. J. G. Grace, when engaged 
on the decoration of the Duke of Hamilton's house, in the 
Isle of Arran, found the woodwork of red pine, so free from 
knots, and so well executed, that instead of painting it, he 



DRY ROT IN TIMBER. ' 193 

had it only varnished. It was a great success, and ten 
years after looked nearly as well as when first done. 

The late Mr. Owen Jones, whose works on colour deco- 
ration are well known, was employed a few years since by 
Mr. Alfred Morrisson to decorate his town and country 
houses. At the country house (Fonthill House), Mr. Jones 
built a room for the display of Chinese egg-shell pottery, 
the chimneypiece and fittings being entirely of ebony, 
inlaid with ivory, and the ceiling of wood, panelled and 
inlaid, the mouldings being black and gold. At the town 
house, in Carlton House Terrace, London, the woodwork of 
the panelling, dadoes, doors, architraves, window-shutters, 
and all the rooms on the ground and first floors is inlaid, 
from designs by Mr. Jones, with various woods of different 
kinds, the colours of which were carefully selected by him, 
with a view to perfect harmony of colouring. 

A house has recently been erected (from the designs 
of Mr. J. W. McLaughlin, architect) near Cincinnati, Ohio, 
United States, which is a perfect model with regard to 
the amount of woodwork used. The walls of the haU 
are finished with walnut wainscoting; the fireplace is an 
open one, with a walnut mantelpiece, surmounted by 
three statues. Peace, Plenty, and Harmony, supporting 
the carved wooden cornice. The Elizabethan staircase 
has carved panels of maple. The library is wainscoted 
to the ceiling in black walnut, inlaid with ebony. The 
dining room is also wainscoted in the richest style in 
oak, with polished mahogany panels. The floors are of 
marquetry, of different woods and patterns. The chamher 
story is finished in oak and walnut, with mahogany in 





194 PREVENTION AND CURE OF 

the panels. The entire interior finish of the house is of 
hard wood, varnished and rubbed in cabinet style. This 
is as it should be for a gentleman's residence. 

We believe the largest house now being erected in 
London is from the designs of Mr. Knowles, jun., for 
Baron Albert Grant, at Kensington. We have not seen 
it, but we hope it will be finished in the Cincinnati 
style, as far as regards the amount of ornamental woods 
used. 

There is a cynical French proverb, which says, " When 
we cannot have what we love, we must love what we have." 
But surely this cynical proverb cannot be applied to 
*' stone colour" paint on wood. The Japanese, however, 
some years since, determined not to follow this advice, for 
when the English Government, at Admiral Sterling's sug- 
gestion, sent to the Tycoon a very fine steam vessel, the 
Japanese (who abhor paint about their ships) immediately 
commenced to scrub off the paint. According to Sir 
Eutherford Alcock, they have been steadily engaged in 
scrubbing it ojff ever since the boat has come into their 
possession, and by dint of labour and perseverance have 
nearly succeeded. All the fine imitation satin-wood and 
the gilt work have been reduced to a very forlorn 
state. The Japanese not only decline to follow advice, 
but they are a very difficult race of people from whom 
to obtain correct information. When Mr. Veitch was at 
Yeddo, on a visit to the Legation, in quest of botanical 
specimens, he saw a pine-tree from which he desired a 
few seeds. "Oh," said the inevitable yaconins, "those 
trees liave no seedl" — "But there they are," replied the 



DRY ROT IN TIMBER. 195 

unreasonable botanist, pointing to some. " Ab, yes, true ; 
but they will not grow',' was the reply. 

If we must take our fashions from royalty and the aris- 
tocracy, and if we must go abroad for them, surely the 
above examples will suffice ; but if we must have paint, 
then the preservative solution, now being extensively used 
in the restoration and renovation of St. Paul's Cathedral, 
under the superintendence of Mr. F. C. Penrose, the archi- 
tect to the Dean and Chapter, appears to possess several 
good qualities. The preservative solution, which is manu- 
factured by the Indestructible Paint Company, is said 
to be as follows : 1st, that it is colourless and invisible ; 
2nd, in no way does it alter the appearance of the surface ; 
3rd, it prevents the growth of vegetation ; and 4th, that it 
resists the action of the atmosphere and changes of weather, 
not only preventing but also arresting decay. 

It is necessary that the wood selected (if not to be 
painted) should be well grown, and from a fully developed 
tree, where all the fibres or grain are distinctly marked. 
The beauty of the wood, when properly treated, consists 
in the brilliant manner in which the rich, deep yellow 
streaks or layers of the hard wood are developed under the 
hands of the skilful polisher. These yellow veins show- 
through the polish like clear and beautifully marked 
streaks of amber ; and strongly reflecting the light, they 
produce a very pleasing effect. The yellow, variegated, 
hard part of the wood forms a very excellent contrast to 
the delicate whiteness of the softer parts of the board ; 
and, if skilfully selected, the effect will be much admired, 
and certainly preferred to the best imitation of the more 

o2 



196 PREVENTION AND CURE OF 

rare and expensive woods. In arranging doors, panels, &c., 
much will, of course, depend in selecting the wood, in 
placing the best parts in the panels, so that when polished 
the most pleasing effects will be produced. Much, too, 
depends on skilful workmanship and smooth finish, which 
can only be obtained by care, and using well-seasoned 
wood; but this is the case with all species of wood. 

Should any young architect, after reading the preceding 
remarks, be desirous of employing natural woods in his 
building works, we advise him, before he attempts this 
kind of colour decoration, to study Mr. Owen Jones' 
lecture on " Colour in the Decorative Arts," delivered 
before the Society of Arts, 1852 ; and likewise M. Chev- 
reul's ' Laws of the Simultaneous Contrast of Colours ' ; we 
also recommend him to — 

Use moderate things elegantly, and elegant things moderately. 

Oak, walnut, maple, elm, and some other woods become 
of very dark colour, but can be made to receive a fine 
polish, and could often be employed for panels with good 
effect. In some cases there is great contrast of tint in the 
same log after preparation, so that these might be inappli- 
cable except in smaller pieces, or perhaps by applying the 
process after the work has been made; but sycamore, 
beech, and some other woods are generally uniform, except 
as regards the previous grain of the wood. 

As to the matter of showing the end of the grain, 
according to the Gothic principle the beauty of a wood 
consists in showing the end of the grain ; but, at the same 



DRY ROT m TIMBER. 197 

time, the classic principle is that there is a greater beauty 
in the side way of the grain than in the end way. 

Although varnish and polish both form a glazing, and 
give a lustre to the wood they cover, as well as heighten 
the colours of the wood, yet from their want of consistence 
they are liable to yield to any shrinking or swelling, rising 
in scales or cracking, when much knocked about. Waxing, 
on the contrary, resists percussion, but it does not possess 
in the same degree as varnish the property of giving 
lustre to the bodies on which it is applied ; any accidents, 
however, to its polish are easily repaired by rubbing. 

The woodwork of the Swiss Cottage, at the late Colos- 
seum, London, in the Eegent's Park, was only varnished. 

In using stain on any description of w^ood, the stain 
should always be allowed to get quite dry before sizing, 
as that gives it a fair chance of striking into the wood. 
Glue size is the best for stained work, made so thin that 
there is no fear of putting it on in patches. After the 
size is quite dry also, varnish ; and if the first coat does 
not stand out quite sufficiently to please the eye, give 
it a second coat. Some persons use stain and varnish 
together, doing away with size ; but this is a very poor 
method, for should the wood get scratched or damaged in 
any w^ay, the varnish and stain come off together, leaving 
a white place, if it be white wood that is stained. A 
painter who has been in the trade forty years, recently 
remarked to us, "You must size, or else the varnish 
won't come out; it won't show that it is varnish; the 
wood soaks it up ; while there is any suction going on 
the varnish 11 go in. The sizing stops all suction." 



198 PREVENTION AND CURE OF 

A great many experiments and attempts have been 
made at different times to colour wood. John of Verona 
first conceived the idea. The celebrated B. Pallissv in- 
vestigated the cause of the veins, &c,, in wood, and tried 
mordant solutions applied to the surface, wetting the sur- 
face with certain acids, immersing the wood in water to 
bring out the veinage, &c. 

Ebony has often been imitated by penetrating sycamore, 
plane, and lime woods to a certain depth with pyrolignite 
of iron, gall-nuts, &c. 

Werner, in 1812, obtained great success at Dijon in 
colouring the woods by filtration. Marloye, in 1833, con- 
structed a machine to colour wood by placing it erect in a 
cylinder, sucking out the air at one end, and forcing up 
the colouring solution through the other. He gave the 
credit of this to Breant. Marloye has manufactured 
many mathematical instruments of wood coloured in this 
way, which does not warp. 

If we could afford the space, we would willingly give 
a resume of the attempts of well known experimentalists 
to colour wood. We can only give the year and name 
in each case : 



1709. Magnol. 
1733. La Baisse. 
1735. Hales. 



1785. Buffon. 
1754. Bonnet. 
1758. Du Hamel. 



1804. Saussure. 



During the recent war between France and Germany, 
the latter country advanced matters, their supplies of 
coloured woods from France being gone. 

As we have made so many remarks against painting 



DRY ROT IN TIMBER. 199 

wood, it is only right that we should give some description 
of it, which we w^ill now do. 

House painting, according to Mr. W. Papworth, in his 
lecture on "Fir, Deal, and House Painting," 1857, did 
not coroe into general use until about the period of 
William and Mary, and Anne, up to which time either 
colouring by distemper or by whitewash had been in 
vogue for plaster work, leaving inside woodwork more or 
less untouched. 

We think, without wishing to think too loud, that house 
painting was invented by a had builder, in the seventeenth 
century, because 

Putty and paint cover a multitude of sins. 

The process of graining and marbling may be traced 
back as far at least as the time of James III. of Scotland 
(1567-1603), during whose reign a room of Hopetown 
Tower was painted in imitation of marble. Before that 
period, imitations were done in "stone" colour, "marble" 
colour, wainscot colour, &c. In 1676, marbling was 
executed as well as imitations of olive and walnut woods ; 
and in 1688 tortoise-shell was copied on battens and 
mouldings. Maghogany was imitated in 1815, and maple 
wood in 1817. But whv imitate mahoranv, when the 
grain of the wood differs so much in texture, and in the 
appearance of the different and beautiful shades, techni- 
cally termed roe, hroheyi roe, hold roe, mottle, faint mottle, 
and dapple. 

The following description will give the reader some 
idea of ordinary painting. The woodwork having been 



200 PREVENTION AND CURE OF 

prepared for fixing, has first to undergo the process of 
" knotting," in order to prevent the turpentine in the 
knots of fir-wood from passing through the several coats 
of paint. One method for best work is to cut out the knot 
whilst the work is at the bench to a slight depth, and to 
fill up the hole with a stiff putty made of white lead, 
japan, and turpentine. There are many ways of killing 
the knots : the best and surest is to cover them with gold 
or silver leaf. Sometimes a lump of fresh slaked lime is 
laid on for about twenty-four hours, then scraped ofi", a 
coating of ^'size knotting" applied, and if not sufficiently 
killed, they are coated with red and white lead in linseed 
oil, and rubbed down when dry. The general method is 
to cover the parts with size knotting, which is a pre- 
paration of red lead, white lead, and whitening, made into 
a thin paste with size. The most common mode is to 
paint them with red ochre, which is worth nothing. The 
next process is that of priming, which consists in giving a 
coat of white and red lead, and a little dryers in linseed 
oil. This is the first coat, and upon which the look of the 
paint on completion depends. This first, or priming coat, 
is put on before " stopping " the work, should that process 
be required. It consists in filling up with putty any 
cracks or other imperfections on the surface of the wood. 
If the putty used in the process of stopping be intro- 
duced before the first coat of colour is laid on, it 
becomes loose when dry. After this first coat, pumicing 
is resorted to for removing all irregularities from the 
surface. It is worth recollecting that old white lead 
is much superior to new for all painting operations. 



DRY ROT IN TIMBER. 201 

A smooth surface being thus obtained, the second coat is 
given, consisting of white lead and oil : about one-fourth 
part of turpentine is sometimes added for quick work. 
If four coats are to be laid on, this second one has some- 
times a proportion of red lead, amounting to a flesh 
colour ; but if only three, it is generally made to assume 
the tint of the finishing coat. It should have a good 
body, and be laid even. This coat, when thoroughly dry 
and hard, is, in best work, rubbed down with fine sand 
paper, and then the third coat, or '^ ground colour," applied 
of a somewhat darker tint than wanted when finished, 
having sufficient oil for easy working, but not too fluid : 
thus two-thirds oil, and one-third turpentine. The 
*^ flatting " coat follows, the object of which is to prevent 
the gloss or glaze of the oil, and to obtain a flat, dead 
appearance. White lead is mixed with turpentine, to 
which a little copal is sometimes added, and when the 
tint is put in it is always made lighter than the ground 
colour, or it would, when finished, appear in a series of 
shades and stripes. Flatting must be executed quickly, 
and the brush is generally, if not always, carried up the 
work, and not across it. 

To clean paint, raw alkalies should not be used, as they 
will infallibly take off the flatting coat. The best mode 
of cleaning is by means of good soap, not too strong, laid 
on with a large brush, so as to make a lather : this should 
be washed off clean with a sponge, and wiped dry with a 
leather. 

We must draw to a conclusion. 

One cause of the decay of modern buildings, and fre- 



202 PREVENTION AND CUBE OF 

quent cases of dry rot, is owing to the employment of bad 
builders. We advise the non-professional reader to em- 
ploy an architect or surveyor when he desires to speculate 
in bricks and mortar : it is the cheapest course. If he 
doubts the truth of what we have written, we can assure 
him he will be a mere child in the hands of a bad or 
scamping builder ; that is to say, he will obtain a badly- 
erected house, — a cheap contract, and a long bill of 
extras. 

There are seven classes of bad builders — 1st, the had 
huilder who does not know his business; 2nd, the had 
huilder who has no money to carry it on with ; 3rd, the 
partial scamp ; 4th, the regular scamp ; 5th, the thorough 
scamp ; 6th, the ''jerry " builder ; and 7th, the vagabond. 
There is an instance of the latter class given by Mr. 
Menzies in his fine work on ' Windsor Park,' 1864. We 
could give examples of all these classes, and draw the 
line between each class, impossible as it may seem : they 
are always looking out for customers, without architects. 

We could assist the non-professional reader by quoting 
the advice given by several architects (viz. Sir C. Wren, 
C. Barry, E. Smirke, W. Chambers, and W, Tite) relative 
to buildings, but there is a Danish proverb which, trans- 
lated into English, runs as follows: "He who builds 
according to every man's advice will have a crooked 
house." 



DRY ROT IN TIMBER. 203 



CHAPTER YIL 

ON THE PRESEKVATION OF WOODEN BRIDGES, JETTIES, 
PILES, HARBOUR WORKS, ETC., FROM THE RAVAGES 
OF THE TEREDO NAVALIS AND OTHER SEA-WORMS. 

" Perforated sore 
And drilled in holes, the solid oak is found 
By worms voracious, eaten through and through." 

Sir John Barrow. 

As the destruction of timber by fungi has been called the 
vegetable rot, it may not be inappropriate to term the de- 
struction of wood by various worms and insects, the 
aniinal rot. 

We have four natural enemies to deal with : 1st, the 
dry rot, that attacks our houses, &c. ; 2nd, the worms, or 
boring animals, which destroy our ships and harbours; 
3rd, the rust, that eats our iron ; and 4th, the moisture 
and gases, that destroy our stone. 

There are three classes of destructive insects which prey 
upon timber trees, founded upon the manner in which they 
carry on their operations — viz. those which feed upon the 
leaves and tender shoots ; those which feed upon the bark 
and the albumen ; and those which feed upon the heart- 
wood. 

It is to be observed that some of the insects which feed 
upon the heart of wood do not cease their ravages upon 



204 PREVENTION AND CURE OF 

the removal of the tree ; but that, on the contrary, the 
Cossus syrex, of our indigenous fauna, and the larvsB of 
the Callidium hajutum, which are often found in imported 
timber, continue to devour the wood long after it has 
been inserted in buildings. There seem to be very few 
means of defence against this class of destructive agents ; 
and very few trustworthy indications of their existence, 
or of the extent of the ravages they have committed, 
are to be discovered externally ; and it thus frequently 
happens that a sound, hearty-looking stick of timber may 
be so seriously bored by these insects as to be of compara- 
tively little value for building purposes of any descrip- 
tion. The soft and tender woaods, and such as are of a 
saccharine nature in their juices, are the most liable to be 
assailed by worms ; those which are bitter are generally, 
if not invariably, exempt; it is obvious, therefore, that 
those palatable juices, which are so conducive to their 
production and propagation, should be got rid of by 
thorough seasoning, and, if further precaution be neces- 
sary, that the inlusion of some bitter decoction into the 
pores of the wood will be an effectual preventive ; and 
for which those woods that are of a regular grain afford 
sufficient facilities. Ash, if felled when abounding in sap, 
is very subject to worms; beech, under similar circum- 
stances, is also liable to their attacks ; likewise alder and 
birch ; in these woods water seasoning is sometimes found 
to be a good preventive ; the sap wood of oak is also thus 
improved ; the silver fir is subject to them ; the sycamore 
is rather so ; alder is said when dry to be very susceptible 
of engendering them ; the cedar, walnut, plane, cypress, 



DRY ROT IN TIMBER. 205 

and mahogany are examples of woods wliich discourage 
their advances. It has been stated that Robert Steven- 
son (not the son of the " Father of Railways "), of Edin- 
burgh, at Bell Eock Lighthouse (of which he was engi- 
neer), between 1814 and 1843, found that greenheart wood, 
beef wood, and bullet tree were not perforated by the 
Teredo navalis, and teak but slightly so. Later experi- 
ments show that the "jarrah" of the East, also, is not 
attacked. Lignum vitse is said to be exempt. The cost 
of these woods prevents their general use. 

In 1810, Stevenson first noticed the teredo in piles, and 
specimens of the creatures in wood were sent to Dr. Leach, 
of the British Museum, in 1811, who examined them, and 
noticed their peculiarities. Stevenson, settled on Bell 
Eock during many years (like a new Eobinson Crusoe), 
was enabled to watch the injuries done to the piles by the 
teredo. With piles which had been subjected to Kyan's 
process before immersion, the wood was attacked at the 
end of the twenty-eighth month, and was entirely de- 
stroyed in the seventh month of the fifth year. With 
Payne's, it lasted a year longer. 

We can give the names of those who have given much 
time and attention to this subject. At the bottom of this 
page a list of works of reference* will be found useful. 
Messrs. Stevenson (engineer of Bell Eock Lighthouse), 
Harting (Member of the Academy of Sciences of the 

* See ' Proceedings of the Royal Society of Edinburgh,' v. 7, pnge 433; 
' Tredgold's Carpentry/ by J. T. Hurst, 1871 ; ' Histoire de I'Acad.,' 17Go, 
page 15; 'Ann. des Fonts et Chausse'es,' v. 15, page 307; 'Mem. sur la 
Conservation des Bois a la Mer,' 1868, by Forestier; ' Bois de Marine,' by 
Quatrefages, 1848. 



20G PREVENTION AND CURE OP 

Pays-Bas), de Quatrafages, Desliayes, Caillaut, Hancock, 
Dagneau, de Gemini, Kater, Crepin (Engineer-in-Chief, of 
Belgium), and A. Forestier (Engineer-in-Chief of the 
Bridges, &c., of France). 

The termite, or white ant, is the most destructive insect 
to timber on land, whilst the teredo reigns supreme of sea 
worms in the sea. The former we shall treat of in our 
next chapter, the latter we propose considering at some 
length in this. 

. The marine worm, of which there are accounts in all 
parts of the world, has been known, by its effects, for 
hundreds of years ; indeed, Ovid spoke of it nineteen 
hundred years ago, and it is even mentioned by Homer. 
Fossil terredines of great antiquity have been found near 
Southend ; also pieces of petrified wood from the green- 
sand, near Lyme and Sidmouth, bored by ancient species 
of teredo ; also from Bath, and from Doulting, near Shep- 
ton Mallet, specimens of oolite, with petrified corallines 
in it, pierced by boring shells. 

It is said that this worm is a native of India, and that 
it was introduced to Holland some 200 years ago, from 
whence it has spread through the ports of northern 
Europe. 

The Teredo navalis^ is very destructive to harbour works 
and piling. The Southampton water is particularly in- 
fested with it; in fact, the teredo is found in every port 
to which coals are carried south of the Tees ; in the 
Thames, as high up as Gravesend ; and northward as far 

♦ There are eight kinds of teredines^ of which three are to be found in 
European waters, viz. the Teredo fatalis, Teredo navalis^ Teredo hipennata. 



DRY ROT IN TIMBER. 207 

as Whitby. It is also found at Eyde, Brighton, and 
Dover. Traces of the ravages of the Teredo navalis, and 
of the Limnoria terebrans, have at various periods been 
found from the north of Scotland and Ireland, on almost 
every coast, to the Cape of Good Hope and Van Dieman's 
Land, in the eastern hemisphere ; and, in the western 
hemisphere, from the river St. Lawrence to Staten Island, 
near Terra del Fuego, almost in the Polar Sea ; so that 
although this maritime scourge is rifest in warm climates, 
yet cold latitudes are not exempt from it. 

At the Crystal Palace, Sydenham, may be seen the 
destructive Teredo navalis in a bottle, and there may 
also be seen mahogany perforated by it, and fir piles from 
Lowestoft Harbour, which were rendered useless by the 
ravages of the worm and the limnoria three years after 
they were driven, showing the necessity of defending 
timber intended for marine construction. A specimen of 
American oak from the dock gates of Lowestoft Harbour, 
which had been four years under water, and a part of a 
fir-pile from the dockyard creek at Sevastopol, also 
show the destructive powers of the teredo. At the South 
Kensington and British Museums, London, specimens of 
this worm may also be seen, as well as pieces of timber 
perforated by it. 

The bottoms of ships, and timbers exposed to the action 
of the sea, are often destroyed by the teredo. 

The gunboats constructed during the Crimean war 
suffered far more from dry rot and the teredo than the 
shot and shell of the Kussians. One cannot even guess 
at the mischief perpetrated every year all along our 



208 PREVENTION AND CURE OF 

shores, in docks and harbours, by the boring animals that 
penetrate all woods not specially protected. We cannot 
count the number of the ships that have foundered at 
sea, owing to those few inches of timber, on which all de- 
pended, being pierced or destroyed by the worm or fungus. 

In the short space of twelve years these destructive 
worms were known to make such havoc in the fir piles 
of a bridgetat Teignmouth, that the whole bridge fell 
suddenly, and had to be totally reconstructed. 

The wooden piers of Bridlington were nearly wholly 
destroyed by worms ; and the pile fenders on the stone 
piers at Scarborough were generally cut through in a few 
years. 

At Dunkirk, wooden jetties are so speedily eaten away 
that they require renewal every twelve or fifteen years. 
At Havre, a stockade was entirely destroyed in six months. 
At Lorient, wood only lasts about three years in the sea- 
water ; and at Aix,-the hull of a stranded vessel was found 
to have lost half its weight in six months, from the 
ravages of these animals. 

The reason why Balaclava, in Kussia, is not a place of 
considerable mercantile importance is owing in a great 
measure to the destructive ravages of the worms with 
which its waters are infested, and by which the hulls of 
ships remaining there for any length of time become 
perforated. 

The piles of the jetties in Colombo Harbour, Ceylon, 
which are mostly of satinwood, and about 14 inches in 
diameter, are so pierced by these worms in the course of 
twelve months as to require renewal. 







i i 



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^^■li 



- * ^ ' .^ '. * i t * ! 



> 9 












4 • * » I 

4 



^ • i. . .'. '^ '^? a . 




Pcr(if>Ti of pile . firm BfiJ/iclnyo harhimr. 
liiuiAUL.'ruiAled ijy Owyll/vdi' S(t\yilis 



DRY ROT IN TIMBER. 209 

The cofferdam at Sheerness was destroyed by the teredo. 
After a time, it was no uncommon occurrence to see several 
piles, apparently sound, floated away at each tide ; indeed, 
they were so thoroughly perforated by the teredo that in 
still weather, by putting the ear to the side of the pile, the 
worms could be heard at their boring labours. 

The almost total destruction of the pier-head of the old 
Southend Pier in a few years, is another instance of the 
serious damages these worms cause. The old pier-head 
was erected in the year 1833, and in three years the 
majority of the wooden piles had been almost destroyed, 
and at the end of ten years, in addition to the piles being 
all eaten through by the worms, the whole structure had 
sunk 9 inches at the western end, so that in a short time 
it would have fallen. The materials with which the work 
was constructed were of good quality, the fir being Memel, 
and the oak of English growth ; it was all perfectly sound 
in those places were the teredo had not attacked it, and 
indeed portions of it were again used in the construction 
of the extension of the pier. The whole of the timber 
work was well coated with pitch and tar previously to 
being fixed, but notwithstanding these precautions, and an 
apparent determination to protect the pier-head by copper 
sheathing, brushing, cleaning, and constant watchfulness, 
the teredo made its appearance, and committed such ravages 
that the entire destruction of the pier-head soon appeared 
inevitable. The Teredo navalis first showed itself six months 
after the completion of the work, and was reported within 
twelve months to have seriously injured the piles above 
the copper, whilst at about low-water mark, of neap tides, 

p 



210 PREVENTION AND CURE OF 

Dearly all the piles exhibited appearances of destruction, the 
Umnoria, as well as the teredo, having seriously attacked 
them ; and in less than four years from the completion of 
the pier-head, they had progressed in their work to such 
an extent that some of the piles were entirely eaten 
through, both above and below the copper sheathing ; in 
consequence of this the stability of the structure was 
materially injured, and, on examination, it was discovered 
that the ground had been considerably washed away by 
the action of the sea, and that the piles below the copper 
were exposed to the action of the teredo. 

The first appearances of the Teredo navalis are somewhat 
singular, inasmuch as the wood which has been perforated 
by it presents to the casual observer no symptom of de- 
struction on the surface, nor are the animals themselves 
visible, until the outer part of the wood has been broken 
away, when their shelly habitations come in sight, and 
show the perfect honeycomb they have formed ; on a 
closer examination of the wood, however, a number of 
minute perforations are discovered on the surface, gene- 
rally covered with a slimy matter ; and on opening the 
wood at one of these, and tracing it, the tail of the animal 
is immediately found, and after various windings and turn- 
ings, the head is discovered, which, in some cases, is as 
much as 3 feet from the point of entrance ; sometimes it 
will happen, especially if the wood has been much eaten, 
that their shelly tubes are partly visible on the surface, 
but this is rare ; they enter at the surface, and bore in 
every direction, both with and against the grain of the 
wood, growing in size as they proceed. 



DRY ROT IN TIMBER. 211 

The Rev. W. Wood writes, in 1863: " I have now before 
me a portion of tlie pier at Yarmouth, which is so honey- 
combed by this terrible creature that it can be crushed 
between the hands as if it were paper, and in many places 
the wood is not thicker than ordinary foolscap. This piece 
was broken off by a steamer which accidentally ran against 
it; and so completely is it tunnelled, that although it 
measures 7 inches in length and about 11 in circumference, 
its weight is under 4 ounces, a considerable portion of 
even that weight being due to the shelly tubes of the 
destrovers." 

The eggs of the teredo aflSx themselves to the wood they 
are washed against, are then hatched, and the worm com- 
mences boring ; each individual serves by itself for the 
propagation of the species; and they rarely injure each 
other's habitations. Any timber, constantly under water, 
but not exposed to the action of the air at the fall of the 
tide, is extremely likely to be destroyed by them. They 
appear to enter the wood obliquely, to take the grain of 
the fibre, and more generally to bore with it downwards, 
where the perforations are left dry at low water. 

It has been stated by some authorities that the teredo is 
only a destructive creature, and seeks the wood as a 
shelter, from instinctive dread of some larger animals, but 
there is no doubt this insect feeds upon wood. Mr. John 
Paton, C.E. (to whom we are indebted for much informa- 
tion on these worms), in conjuction with Mr. Newport, the 
eminent physiologist and anatomist, on carefully dissect- 
ing this animal for the purpose of ascertaining its general 
character, and more particularly the nature of its food, 

p 2 



212 PFEVENTION AND CURE OF 

found digested portions of wood in its body, so that there 
is no doubt that the teredo does feed upon the particles of 
the wood, and to this its rapid and extraordinary growth 
must be mainly attributed. 

The Teredo navalis^ or, as it is sometimes called, the 
Ship AVorm, is one of the Acephalous moUusca, order Con- 
chifera, and of the family of the Pholadarise. It is of an 
elongated vermiform shape, the large anterior part of which 
constitutes the boring apparatus, and contains the organs of 
digestion, and the posterior, gradually diminishing in size, 
those of respiration. The body is covered with a trans- 
parent skin, through which the motion of the intestines 
and other remarkable peculiarities are plainly visible. 
The posterior or tail portion is armed at its extremity, 
with two shells, and has projecting from it a pair of 
tubular organs, through which the water enters, for the pur- 
pose of respiration ; this portion is always in the direction 
of the surface, and apparently in immediate contact with 
the water, but does not bore. The anterior portion of the 
animal is that by which it penetrates the wood, being well 
armed for the purpose by having, on each side, a pair of 
strong valves, formed of two pieces, perfectly distinct from 
one another ; the larger piece protects the sides and sur- 
face of the extremities, and has a shelly structure projecting 
from the interior, to which the muscles are attached ; the 
smaller piece is more convex, and covers that part which 
should be regarded as the anterior surface of boring. This 
portion of the shell is deeply carniated, and seems to con- 
stitute the boring apparatus. The shells form an envelop 
around the external tegument of the animal, which even 



I 



k 

^ 






•2 

I 




.(1 



I 

I 



5^ 



ForiioTi of Timber piJU cUstroyedj by 
Seatworms. 



DRY KOT IN TIMBER. 213 

surrounds the foot, or part by ^vhicll it adheres to the 
wood. The neck is provided with powerful muscles. The 
manner in which it appears to perforate the wood is by a 
rotary motion of the foot, carrying round the shells, and 
thus making those parts act as an auger, which is kept, or 
retained in connection with the wood, by the strong ad- 
herence of the foot. The particles of wood removed by this 
continued action of the foot, and the valves, are engorged 
by the animal, for between the junction of the two large 
shells there is a longitudinal fissure in the foot, which 
appears to be formed by a fold of this portion of the two 
sides, thus forming a canal to the oral orifice, and along 
which the particles of wood bored out, are conveyed to 
the mouth. The mouth, or entrance to the digestive 
organs, is of a funnel shape, and consists of a soft, or 
membraneous surface, capable of being enlarged, and lead- 
ing into an oesophagus, which passes backwards towards 
the dorsal surface of the animal. At or near the termina- 
tion of the oesophagus, there is a glandular organ, the use 
of which is possibly to secrete a fliuid for assisting in the 
digestion of the wood, and not, as has been supposed, to 
act as a solvent ; for if such were the case, it would most 
probably be situated at its commencement instead of at its 
termination. At a short distance behind this organ are 
two other large glandular bodies, the use of which may 
also be to secrete fluid for the purpose of digestion. The 
oesophagus terminates in a large dilatation, into which 
these organs pour their contents ; at its posterior end the 
canal is dilated into a very large elongated sac, which 
extends backwards to about one-fourth of the length of 



214 PREVENTION AND CURE OF 

the whole animal, and is filled with food, while from its 
anterior, or upper surface, it has an oval, muscular forma- 
tion, from which the alimentary canal is continued for- 
wards, and, after making a few turns, passes backwards, in 
an almost direct line, on the upper surface of the large sac, 
again passing backwards and forwards, until it finally 
arrives at its termination, which it passes round, and then 
proceeds, in a direct line, to the anal outlet. In the lower 
portion of the oesophagus, and also in the sac, distinct por- 
tions of woody fibre of an extremely minute character 
were found by the aid of the microscope of a power of 
three hundred, and this was the character of the whole 
of the contents of the alimentary canal. 

The teredo lines the passage in the wood with a hard 
shell ; this shell is formed around, but does not adhere to 
the body ; it is secreted by the external covering, which, 
in its first formation, is extremely fragile, but becomes 
hardened by contact with the water, and adheres to the 
wood, from which it may, however, be easily detached. 
The interior of this shell is not filled by the body of the 
teredo, but a large space around it is occupied with water, 
admitted through the small orifice in the surface of the 
wood through which the animal first entered ; the water 
being drawn through the respiratory tubes, into the bron- 
chial cavity of the body, is expired again through the 
same orifice, and this, in conjunction with the valve-like 
shells attached at this part, induces a current round the 
animal which removes the excreted foetal matter. The 
shells are very smooth on the inner surface, but are some- 
what rougher on the exterior ; they are much harder and 



DRY ROT IN TIMBER. 215 

firmer in the cells of the older animals than in the young 
ones, and are composed of several annular parts, differing 
greatly in their length. 

It is no less curious than wonderful to observe the mys- 
terious instinct which apparently regulates the mechanical 
skill of the teredo, its own body supplying it with an im- 
plement of such admirable consistency and adaptation as 
to enable it to excavate a habitation for itself, so accurately 
formed that to a casual observer it would appear a mys- 
tery how so perfect a circle could be produced. It is only 
on examination that the raised and hollow parts of the 
w^ood become visible, and explain, in some degree, the 
auger-shaped contrivance that has been used for the pur- 
pose of perforating. 

It has already been stated, that the wood is perforated 
by a rotary motion of the foot, the adhering part of which 
acts as a fulcrum, carrying round the shells, and thus 
giving immense power to the animal in its operations. 

It is said that when Brunei was considering how to con- 
struct the Thames Tunnel, he was one day "passing through 
the dockyard (at Chatham, where he was employed by 
Government), when his attention was attracted to an old 
piece of ship-timber which had been perforated by that 
well-known destoyer of timber — the Teredo navalis. He 
examined the perforations, and subsequently the animal. 
He found it armed with a pair of strong shelly valves, 
which enveloped its anterior integuments ; and that, with 
its foot as a fulcrum, a rotatory motion was given by 
powerful muscles to the valves, which, acting on the wood 
like an auger, penetrated gradually but surely ; and that, 



216 PREVENTION AND CURE OF 

as the particles were removed, they were passed through 
a longitudinal fissure in the foot, which formed a canal to 
the mouth, and so were engorged. To imitate the action 
of this animal became Brunei's study. ^From these 
ideas,' said he, ' by slow and certain methods ; which, 
when compared with the progress of works of art, will be 
found to be much more expeditious in the end.' " * 

Professor Owen suggests that the power of the teredo to 
bore into wood depends on muscular friction, the muscular 
substance being perpetually renewed while the wood wastes 
away, of course, without renewal. Professor Forbes, Dr. 
Carpenter, and Dr. Lyon Playfair were appointed about 
twenty-five years ago by the British Association to examine 
into the natural history and habits of these boring ani- 
mals, but they did not arrive at any definite conclusion 
as to whether the boring action of the teredo was mecha- 
nical or chemical. Dr. Deshayes, on his return from 
Algiers, after making accurate drawings and careful in- 
vestigations, came to the conclusion that the borings were 
effected by an acid secretion. Mr. Thomson, of Belfast, 
examined the operations of the teredo on the pier at Port 
Patrick, and arrived at the same conclusion. The general 
opinion, however, is that the boring action is a mechanical 
one. 

Although the teredo appears to penetrate all kinds of 
timber, that which it seems to destroy with the greatest 
ease is fir, in which it works much more speedily and 

* See * Memoirs of Sir M. I. Brunei; * also, for particulars of the con- 
struction of the shield designed by him for forming the Tunnel, AVeale's 
' London Exhibited,' and ' A Memoir of the Thames Tunnel,' in Weale's 
Quarterly Papers on Engineering. 




i 




^ 




SheW 

left by the 

Teredo MjL¥ciUs. 



CeH formPjdj by tlie Teredo NoA/alOi 
s}w\s'inxj method of hnring. 



DRY ROT IN TIMBER. 



217 



successfully than in any other, and perhaps grows to the 
greatest size. In a fir pile, taken from the old pier-head 
at Southend, a worm was found 2 feet long and 3 ii^<^'ti in 
diameter, and indeed they have been heard of 3 feet in 
length and 1 inch in diameter. The soft, porous nature 
of the wood is no doubt the cause of their rapid growth, 
for in oak timber they do not progress so fast, or grow to 
so great a length, though in Sir Hans Sloane's 'History 
of Jamaica' (1725) there are accounts of these animals 
destroying keels of ships made of oak, and even of cedar, 
although the latter is renowned, by its smell and resin, 
for resisting all kinds of worms. 

There is another kind of worm which is very destructive 
to timber, which Smeaton observed in Bridlington piers. 
This is the Timber-boring Shrimp, or Gribble, the 
Limnoria terebrans (or Limnoria perforata, Leach), a 
mollusc of the family Asselotes, Leach. The Limnoria 
terebrans is very abundant around the British shores. Its 
ravages were first particularly observed in the year 1810, 
by the late Blr. Kobert Stevenson, engineer of the Bell 
Rock Lighthouse. While engaged in the erection of that 
structure he found the timber of the temporary erections 
to be soon destroyed by the attacks of the limnoria. So 
little was known of the limnoria at the time that Dr. 
Leach, a well-known naturalist, who received some speci- 
mens from Mr. Stevenson, in 1811, declared it to be a 
new and highly interesting species. In 1834, the late Dr. 
John Coldstream wrote a very full and interesting descrip- 
tion of the creature. The limnoria resembles a woodlouse, 
and is so small as hardly to be perceptible in the timber it 



218 PREVENTION AND CURE OF 

attacks, being almost of the same colour. Small as is this 
crustacean, hardly larger indeed than a grain of rice, it is 
a sad pest wherever submarine timber is employed, for it 
works with great energy, and its vast numbers quite com- 
pensate for the small size of each individual ; for as many 
as twenty thousand will appear on the surface of a piece 
of a pile only 12 inches square. It proceeds in a very 
methodical manner, and makes its way obliquely inward, 
unless it happens to meet a knot, when it passes round the 
obstacle and resumes its former direction. The surface of 
the timber being first attacked, it proceeds progressively 
into the wood to the depth of about 1^ inch : the tunnels 
being cylindrical, perfectly smooth winding holes, about -re th 
inch in diameter : it is necessary that the holes should be 
filled with salt water. The outward crust formed by these 
attacks then becomes macerated and rotten, and is gra- 
dually washed away by the beating of the sea. The lim- 
noria does not work by means of any tool or instrument 
like the teredo, but is supposed to possess some species of 
dissolvent liquor, furnished by the juices of the animal 
itself. Dr. Coldstream was of opinion that the animal 
effects its work by the use of its mandibles. From lig- 
neous matter having been found in its viscera, some have 
concluded that it feeds on the wood, but since other 
molluscs of the same genus, Pholas, bore and destroy 
stonework, the perforation may serve only for the animal's 
dwelling. The limnoria seems to prefer tender woods, 
but the hardest do not escape : teak and green-heart are 
about the only woods it does not attack. The rate at 
which the limnoria bores into wood in pure salt water is 



DKY liOT IN TIMBER. 219 

said to be about one inch in a year; but instances have 
occurred in which the destruction has been much more 
rapid. At Lowestoft Harbour, square 14 inch piles were 
in three years eaten down to 4 inches square. At Gree- 
nock, a pile 12 inches square was eaten through in seven 
years. It is stated that a 3-inch oak plank, 12 feet long, 
would be entirely destroyed in about eight years. Joists 
of timber have been found at Southend Pier, 2 feet and 
3 feet below high-water mark, where they had made rapid 
destruction. The limnoria almost always works just under 
neap tides ; it cannot live in fresh water, and whilst it is 
destroying the surface of a pile, the teredo is attacking 
the interior : sometimes the former is found attacking the 
same timber as the Chelura. As with most of these crea- 
tures, the male limnoria is smaller than the female, being 
about one-third her size. The female may be distinguished 
by the pouch in which the eggs and afterwards the young 
are carried. About six or seven young are generally found 
in the pouch. 

The WooD-BORiNG Shrimp {Chelura terebrans) is a 
crustacean that nearly rivals the teredo itself in its de- 
structive powers. It makes burrows into the wood, wherein 
it can conceal itself, and at the same time feast upon the 
fragments, as is proved by the presence of woody dust 
within its interior. Its tunnels are made in an oblique 
direction, not very deeply sunk below the surface, so 
that after a while the action of the waves washes away 
the thin shell, and leaves a number of grooves on the 
surface. Below these, again, the creature bores a fresh 
set of tunnels, which in their turn are washed away, so 



220 PREVENTION AND CURE OF 

that the timber is soon destroyed in successive grooved 
flakes. 

According to Mr. Allman, its habits can be very easily 
watched, as if it is merely placed in a tumbler of sea 
water, together with a piece of wood, it will forthwith 
proceed to work, and gnaw its way into the wood. The 
apparatus with which it works this destruction is a kind of 
file or rasp, which reduces the wood into minute frag- 
ments. In this creature the jaw feet are furnished with 
imperfect claws, and the tenth segment from the head is 
curiously prolonged into a large and long spine. The 
great flattened appendages near the tail seem to be 
merely used for the purpose of cleaning its burrow of wood 
dust which is not required for food. The creature always 
swims on its back, and when commencing its work of 
destruction, clings to the wood with the legs that proceed 
from the thorax. The wood-boring shrimp is one of the 
jumpers, and, like the sand hopper, can leap to a con- 
siderable height when placed on dry land. It has been 
detected in timber taken from the sea at Trieste. It was 
first observed as an inhabitant of the British seas several 
years ago, by Mr. Kobert Ball, of Dublin, and in January, 
1847, it was described by Mr. Mullins, C.E., in a paper 
read before the Institution of Civil Engineers of Ireland, 
as being very injurious to the timber piles in Kingstown 
Harbour, near Dublin, and far more destructive than the 
Limnoria terebrans. 

We have already referred to the lesson the celebrated 
engineer, Brunei,"^; received from observing the teredo ; 
and we can state that architects have also received lessons 



LIMNORIA TEREBRANS. 




CHELURA TEREBRANS 




!^f^ 



ELEVATION of PILES, SOUTHEND PIER, DESTROYED by THt"TEREDO'AND LIMNORIA 
ABOVE AND BELOW the COPPER SHEATING. 



DRY ROT IN TIMBER. 



221 



from nature. Sir Christopher Wren constructed his spire 
of St. Bride's Church, London, after observing the con- 
struction of the delicate shell, called TurreteUa, ^vhich 
has a central column, or newel, round which the spiral 
turns. Brunelleschi designed the dome of Sta. Maria, at 
Florence, after studying the bones of birds and the human 
form ; and Michael Angelo followed Brunelleschi in con- 
structing the dome of St. Peter's, Kome.* 

The LEPIS3IA is also a destructive little animal, which 
begins to prey on wood in the East Indies, as soon as it is 
immersed in sea water. The unprotected bottom of a boat 
has been known to be eaten through by it in three or four 
weeks. 

These worms, it must be remembered, do not live 
except where they have the action of the water almost 
every tide, nor do they live in the parts covered with 
sand. The wooden' piles of embankments and sea locks 
suffer very much from their depredations, and in the sea 
dykes of Holland they cause very expensive annual 
repairs. 

The Dutch used to coat their piles with a mixture of 
pitch and tar, and then strew small pieces of cockle and 
other shells, beaten almost to powder, and mixed with 
sea sand, which incrusted and armed the piles against 
the attacks of the teredo. We believe it was a frequent 
practice in London, about half a century ago, to place 
small shells in the wooden pugging between the floor 
joists to deaden sound. 

Having described the cliief peculiarities of these worms, 

* Note geometrical framing in spider's web. 



222 PREVENTION AND CURE OF 

shown their mode of working, and the extent to which 
their destructive powers may be carried, it will now be 
necessary to consider the various schemes which have been 
proposed and tried to prevent their desolating ravages. 
These may be divided into three classes, viz. the natural, 
chemical, and mechanical. 

1st. By using woods which are able to resist the attacks 
of sea worrns. 

2nd. By subjecting piles to a chemical process. 

3rd. By adopting a mechanical process. 

First. We have not any English woods which resist 
their attacks. Elm (used for piles in England) or beech 
(used for piles, if entirely under water, in France) cannot 
withstand the teredo ; while oak cannot battle successfully 
against wood-beetles in carvings. It is therefore neces- 
sary to inquire whether foreign woods are any better.* 
Unfortunately the great expense of importing them into 
England prevents their use for piles. 

Nearly all our foreign woods used for engineering and 
building purposes come from the Baltic or Canada : they 
are fir and pine. Memel timber from the Baltic is 
comparatively useless unless thoroughly creosoted; and 

* * Reports of the Juries,' Exhibition, 1851. ' Reports' by Dr. Gibson, 
Conservator of Forests, Bombay Presidency. * Reports ' by Dr. CIcghorn, 
Conservator of Forests, Madras Presidency. ' Reports ' by Mr. H. B. Baden 
Powell, Inspector-General of the Forest Department, India, 1875. 'Reports' 
on the Teak Forests of Tenasserim, Calcutta, 1852. Papers by Mr. Mann 
and Mr. Heath on 'Decay of Woods in Tropical Climates,' Inst. C.E., 
1866. Paper on ' The Ravages of the Limnoria Terebrans,' by Mr. R. 
Stevenson, Royal Society, 1862. 'Account of the Bell Rock Lighthouse,' 
by Robert Stevenson, 1824. Stevenson's 'Design and Construction of 
Harbours.' Smeaton's ' Reports.' 



DBY ROT IN TIMBER. 223 

Canadian timber is not so good as the Baltic wood. At 
Liverpool and some of the western ports of England 
Canadian timber is preferred to Baltic, although we 
believe the reason to be that they cannot get the latter, 
except in small quantities at a time. 

The following is a list of timber woods which, according 
to good authorities, resist for a long period of time the 
attacks of sea worms. It should be borne irrmind, how- 
ever, that the timber should be cut, during the proper 
season, from a large and full-grown tree ; and, to prevent 
splitting, it should be kept from the direct action of the 
sun when first cut; it should have all the bark and 
sapwood removed, and allowed to dry a certain time 
before being used. 

WOODS WHICH RESIST SEA WORMS. 

Australia^ Western. — Jarrah, beef- wood, tuart. 

Bahama, — Stopper- wood . 

Brazil. — Sicupira, green heart. 

British Guiana, — CabacaUi, greenheart, kakarilly, silverballi (yellow). 

Ceylon. — Halmalille, palmyra, theet-kha, neem. 

Demerara. — Bullet, greenheart (purple heartwood), sabicu. 

India. — Malabar teak, sissoo, morung sal, dabu, than-kya, ilupe', anan, 
angeli, may-tobek. (Teak resists the teredo^ but is not proof against 
barnacles.) 

Jamaica. —Greenheart. 

North America. — Locust. 

Sierra Leone. — African oak, or tortosa. 

South America. — Santa Maria wood. 

Philippine Islands. — Malacintud, barnaba, palma-brava. 

Tasmania. — Blue gum. 

West Indies. — Lignum vitse. 

Second. The chemical, viz. Eyau's process of corro- 
sive sublimate; Payne's process of sulphate of iron and 



224 PREVENTION AND CURE OF 

muriate of lime ; pitching and tarring ; Burnett's process 
of chloride of zinc ; and arsenic, or other mercurial pre- 
parations, have all failed, with the exception of Bethel Fs 
process of oil of tar. The failure must proceed from one 
of two causes; either that the sea-water decomposes the 
poisonous ingredients contained in the wood, or that these 
poisonous compounds have no injurious effect on the worms; 
it appears, liowever, that both these causes have been in 
operation, principally the latter. 

Without a series of the most minute experiments, it is 
impossible to form any general notion of the action of 
sea-water on timber. Common salt, chlorides of calcium 
and magnesium, sulphate of soda, iodides and bromides 
of the same metals, are known to exist in sea-water, and 
in great abundance in the torrid zone. What effect these 
different ingredients may have upon saturated timber it is 
difficult to say, but it is extremely probable that they do 
have an effect. 

With regard to the different poisonous compounds 
having no injurious effect on the worms, it should be 
remembered that all cold-blooded animals are much more 
tenacious of life than those of a higher temperament, and 
in descending the scale of animal creation, the tenacity of 
life increases, and this principle is more developed. A 
frog, which though cold-blooded, is an animal of a much 
higher order than the teredo, will not only live in hydrogen 
gas, but also in a strong solution of hydrocyanic acid, 
while at the same time a single drop placed on the nose 
of a rat, or in the eye of a rabbit, would produce instant 
death. A somewhat similar occurrence is noticed in the 



DRY ROT IN TIMBER. 225 

'British and Foreign Medical Eeview/ for July, 1841, 
showing the slow effects of prussic acid on the common 
snake and turtle. 

It may therefore be inferred, that as it requires a large 
quantity of the most virulently poisoned matter to destroy 
animals of a much higher order than the teredo^ it would 
take a still greater quantity to affect those animals as 
they exist in their own element. 

The preserving property of soluble salts, such as corro- 
sive sublimate, sulphate of copper, &c., was considered to 
be founded upon their power of coagulating the albumen, 
and the sap of wood, thereby rendering that sap less liable 
to decay ; but that very quality of combining with the 
albumen, destroyed the activity of the poison of the salts. 
A given quantity of corrosive sublimate of mercury, which 
if administered to a dog would kill it, would, when mixed 
with the w^hite of an egg, become coagulated, and if 
swallowed in that state w^ould be perfectly harmless ; so a 
piece of wood, saturated by those salts, could be eaten by 
a worm without injury. 

A French naturalist, M. de Quatrefages,* in 1848, sug- 
gested that a weak solution of mercury (corrosive subli- 
mate) thrown into the water will destroy the milt of 
the teredo, and consequently prevent fecundation of the 
eggs, thus exhausting the molluscs in the bud. He 
proposed that ships should be cleared of this terrible pest 
by being taken into a closed dock, into which a few 
handfuls of corrosive sublimate should be thrown and 

* See * Sur un Moyen de Mettre tous les Appro visionnements de Bois 
de la Marine de la Piqure des Tarets' (Compte. rend., Janv. 1848). 

Q 



226 PREVENTION AND CURE OF 

well mixed with the water. He considered that about 
1 lb. of sublimate would be suflScient for 20,000 cubic 
metres (metre = 39 * 37 English inches) of water ; but on 
account of the cost it would be advisable to use salts of 
lead or copper. This proposition of de Quatrefages 
reminds us of Chapman's suggestion, in 1812, to get rid 
of dry rot in ships, viz. by sweeping out the hold, laying 
from two to four tons of copperas in her bottom, and as 
much fresh water let in upon it as would make a saturated 
solution to soak into the wood. 

M. de Quatrefages placed the four salts he used in 
his experiments in the following order, according to 
merit : 1st, corrosive sublimate ; 2nd, acetate of lead ; 
3rd, sulphate of copper ; and 4th, nitrate of copper. 

In America, white oxide of zinc is used as a marine 
paint for ships and piles. In the United States Navy 
Yard at Gosport it is spoken well of, and very frequently 
employed. It is said to be much superior to white-lead, 
red-lead, verdigris, or coal-tar, and that timber covered 
with two coats of white zinc is neither attacked by the 
worm, nor do barnacles attach to it when immersed in 
salt water. 

We can only find one instance of timber impregnated 
with water-glass having been tested against this subtle 
foe. Water-glass is certainly worth a further trial. 

The instance we refer to occurred about forty years 
ago. In 1832, Dr. Lewis Feuchtwanger, of New York, 
was permitted by the Ordnance Department, under the 
direction of Commodore Perry, to perform experiments 
with water-glass on piles in the Brooklyn Navy Yard, and 



DRY ROT IN TIMBER. 227 

in various docks. The piles in tlie docks were destroyed 
by the teredo so fast that they had to he replaced every 
three years. The experiments proved highly satisfactory : 
the piles which had been so treated lasting many years, 
without any indication of being attacked by sea-worms. 

The reader is referred to some works on water-glass 
mentioned below,* which are worthy of attentive perusal. 

Third. The mechanical processes. They are few in 
number, and rather expensive. 

At Saint Sebastian, in Spain, the piles of the wooden 
bridge standing in the sea have been guarded against 
the attacks of sea-worms in the following manner : Each 
pile is surrounded by a wooden box, and the space between 
filled up with cement. After six years it was proved that 
the piles were in a perfect condition, whilst the outer 
boxes were completely riddled by the worms. A similar 
method to this was adopted, some years since, to many of 
the piles in the Heme Bay Pier, which were affected by 
sea-worms. Several attempts had been made to protect 
the timber, by saturating it under various processes, with, 
however, only doubtful success. At last, a wooden casing 
was formed round each pile, leaving a space of about an 
inch all round, which w^as rammed full of lime or cement 
concrete. That process appeared to be perfectly suc- 
cessful, as the pier-master, who first adopted the method, 
stated that some of the piles had been so treated for three 
or four years, and although the worms had commenced 

* * Report of German Commission relative to rendering Woodwoik "^nd 
Stage Materials Incombustible.* Professor Fuch's and Dr. Pettenkofer'a 
Reports. Dr. Feuchtwanger*s works. M. Kuhlman's pamphlet. ' Reports 
relative to Ransome's Process.' Note M. Szerelmey's patent, 21 July, 1SG8. 

q2 



228 PREVENTION AND CURE OF 

their ravages, tliey appeared to have been checked, and 
not to have been able to exist when so enclosed. 

In 1835, Brunei suggested an easy way of defending 
piles, which was to give them in the first instance a coat 
of tar; then powder them with brick-dust, which would 
render the wood sufiSciently hard to receive a coat or two 
of cement. This is similar to the Dutch method. 

Some foreigners use sheet lead nailed on to piles, and 
wrapped close round with well-tarred rope. 

Copper sheathing has often been used for the protection 
of piling in piers and harbours. The destruction of 
copper by the action of sea-water is a matter which has 
long occupied the attention of scientific men, and it 
appears to be well ascertained that the decay does not 
result from the bad quality of the copper, for, according to 
Mr. Wilkinson, no difference could be discovered between 
the composition of copper that had endured well, and that 
which had been rapidly destroyed. Copper sheathing 
was used at Southend, but without success, for although 
nearly all the piles were covered with it for about 9 feet 
or 10 feet, the limnoria not only penetrated between the 
copper and the timber, but the copper had decayed to 
such an extent as in some cases to be no thicker than the 
thinnest paper ; it was soft, and peeled off the wood very 
easily, and in two or three years would probably have 
been entirely destroyed. 

Covering the surface of the timber with broad-headed 
scupper nails, arranged in regular rows with their heads at 
no great distance from each other, is a method which has 
been satisfactorily employed in various parts of the world, 



DRY ROT IN TIMBER. 229 

in Swedish and Danish vessels, even up to the present 
time, and, indeed, it was also practised by the Romans. 
The scupper-nailed piles at Southend, after twelve years' 
exposure to the sea, were perfectly sound, and although 
the nails were not driven close together in the first 
instance, yet the corrosive action was so great as to form 
a solid impenetrable metallic substance, upon which the 
worms refused to settle. Scupper nails have been proved 
at Yarmouth, as well as at other places, to have protected 
timber for forty years, but the process is expensive, as it 
costs one sliilling per square foot. They should be about 
half an inch square at the head. 

Captain Sir Samuel Brown, R.N., states that from 
numerous experiments and observations, he is satisfied 
that at present there is really no specific remedy against 
the attacks of sea-w^orms upon timber, except iron nails. 
He proposes to encase the piles with broad-headed iron 
nails resembling scupper nails, but considerably larger, 
and he says that in the course of a few months corrosion 
takes place, and spreads into the interstices. The rust 
hardens upon the pile, and becomes a solid mass which the 
worm will not touch. Experiments tried at the Trinity 
Pier, Newhaven, and Brighton Pier, have established the 
effectiveness of his method. 

At the Cape of Good Hope, and many other places, 
wood piles are cased in iron, and occasionally iron piles 
are used instead of wood, at great cost. Further experi- 
ence is desirable as to the durability of cast iron * in salt 

* See ^ Memoirs on the Use of Cast Iron in Piling/ by Mr. M. A. Bortb- 
wick, ' Trans. Inst. Civ. Eng.,* vol. i. No. 22. 



230 PREVENTION AND CURE OF 

Avater, especially as to its peculiar property of conrersion, 
after a few years' immersion in the sea, into a carburet of 
iron, closely resembling plumbago, so that it may be 
easily cut with a knife. This, of course, diminishes its 
powers of resistance acting upon the framing it is intended 
to strengthen. In the course of the construction of the 
Britannia Bridge, about one hundred thin plates were 
delivered, which were not used on account of some error 
in their dimensions. They were left on the platform 
alongside the straits, exposed to the wash and spray of 
the sea ; and after about two years were literally so 
completely decomposed as to be swept away with a broom 
into the water, not a particle of iron remaining. 

We have already stated that the chemical processes 
have failed with the exception of Bethell's process of oil 
of tar, generally known as the creosoting process. This 
method, when jpro^erly carried out, thoroughly protects 
wood from the ravages of the teredo and other marine 
worms. The breakwaters and piers at Leith, Holyhead, 
Portland, Lowestoft, Great Grimsby, Plymouth, Wisbeach, 
Southampton, &c., have been built with creosoted timber, 
and in no case have the Teredo navalis, Limnoria terebranSy 
or any other marine worms or insects been found to 
attack these works, as certified to by the engineers in 
whose charge the several works are placed. In the cases 
of Lowestoft and Southampton we are enabled to give the 
detailed reports. 

A most searching examination, lasting many days, was 
made in 1849, upon every pile in Lowestoft Harbour, by 
direction of Mr. Bidder ; and the report of Mr, Makinson, 



DRY ROT IN TIMBER. 231 

the Superintendent of Lowestoft Harbour Works, con- 
tains the subjoined statement : 

'' The following is the result, after a close and minute 
investigation of all the piles in the North and South Piers. 

*' North Pier. — The whole of the creosoted piles in the 
North Pier, both seaward and inside the harbour, nine 
hundred in number, are sound, and quite free from teredo 
and limnoria, 

" South Pier, — The whole of the creosoted piles in the 
South Pier, both seaward and insideHhe harbour, seven 
hundred in number, are sound, and quite free from teredo 
and limnoria, 

" There is no instance whatever of an uncreosoted pile 
being sound. They are all attacked, both by the limnoria 
and the teredo, to a very great extent, and the piles in 
some instances are eaten through. All the creosoted 
piles are quite sound, being neither touched by the teredo 
or tlie limnoria, though covered with vegetation, which 
generally attracts the teredo.^' 

There was only one instance of a piece of creosoted 
wood, in Lowestoft Harbour, being touched by a worm, 
and that was occasioned by the workmen having cut away 
a great part of one of the cross heads, leaving exposed the 
interior or heart of the wood, to which the creosote had 
not penetrated. At this spot a worm entered, and bored 
to the right, where it found creosote ; on turning back 
and boring to the left, but finding creosote all around, its 
progress was stopped, and it then appeared to have left 
the piece of wood altogether. 

In 1849, Mr. Doswell, who had the conduct of experi- 



232 PREVENTION AND CURE OF 

ments on different descriptions of wood at Southampton, 
where the river was so full of the worm that piles of 
14 inches square had been eaten down to 4 inches in four 
years, reported as follows : ^^ From my examination, last 
spring tides, of the specimen blocks attached, on the 22nd 
February, 1848, to some worm-eaten piles of the Eoyal 
Pier, I am enabled to report that Bethell's creosoted 
timbers all continue to be unaffected by the worms ; that 
the pieces saturated with Payne's solution continue to 
lose in substance by their ravages ; and that the unpre- 
pared timbers diminish very fast, except the American 
elm, which stands as well (or nearly so) as that prepared 
by ' Payne's solution.' " 

The following are the detailed particulars : 

Bethell's Creosoted Blocks, placed February 22, 1848. 

Memel, at low water of sprinsr tides . . 1 tt ^v x j t, 

^ , .' , , „ . , !" Unaffected by worms. 

Ked pine, at low water of neap tides . . ; 

Yellow fir, at high water of neap tides . . A few barnacles. 

Paynized Blocks, placed April 6, 1848. 
Red pine, at low water of spring tides . . Worm-eaten. 
American elm, at low water of neap tides ] a f >^ i 
Fir, at high water of neap tides . . . . i^ 

Unprepared Blocks, placed April 6, 1848. 
Memel, at low water of spring tides . . Much worm-eaten. 
American elm, at low water of neap tides A few barnacles. 
Fir, at high water of neap tides . . . . Much worm-eaten. 

On 1st January, 1852, Mr. Doswell ascertained that, 
notwithstanding the number of teredines and limnoria to be 
found in the Southampton Waters, none of the creosoted 
blocks had been attacked by them. 



DRY EOT IN TIMBER. 233 

According to M. Forestier, similar results have been 
obtained at Brighton, Sunderland, and Teignmouth. 

Allusion has already been made to Mr. Pritchard, of 
Shoreham, with reference to preserving timber. On 
July 26, 1842, he presented a report to the Treasurer of 
the Brighton Suspension Chain Pier Company, upon the 
preservation of timber from the action of sea-worms. We 
give a portion of it, as follows : 

"Stockholm tar has been used, and proved to be of 
little service ; this tar is objectionable owing to its high 
price, and also from its being manufactured from vegetable 
substances. All tars containing vegetable productions 
must be detrimental to the preservation of timber, 
especially when used in, and exposed to, salt water. This 
tar does not penetrate into the wood, and in a very few 
months the salt acid of the sea will eat it all away. 

"Common gas or coal tar has been used to a great 
extent, and its effects are apparent to all. It does a very 
great deal of harm, forms a hard or brittle crust or coat 
on the w^ood, and completely excludes the damp and 
unnatural heat from the possibility of escape, owing to its 
containing ammonia, which burns the timber, and in a 
few years it turns brown and crumbles into dust. Indeed, 
timber prepared with this tar will be completely destroyed 
on this coast and pier by the ravages of the Teredo navalis, 
and the Limnoria terehrans, in five or six years. 

'^ Also Kyan's patent, or the bi-chloride of mercury, has 
been used, but has proved equally useless. The sleepers 
Kyanized five years ago, and in use at the West India 
Dock warehouses, have been discovered to decay rapidly, 



234 PREVENTION AND CUBE OF 

and the wooden tanks at the Anti-Dry-Eot Company's 
principal yard are destroyed. 

'^ I would recommend you for the future to use ' oil of 
tar and pyrolignite of iron' (Bethell's patent). This 
process will, without a doubt, succeed. I have proved in 
hydraulic works on this coast that it will fully prevent 
the decay in timber piles, destroy sea- worms, and super- 
sede the necessity of coating the piles with iron nails. In 
Shoreham Harbour, for instance, there is a piece of red 
pine accidentally infused with pyrolignite of iron, which 
after being in use tw^elve years is perfectly sound. 
There is another waleing piece, the very heart of English 
oak, Kyanized, and in use only four years, which is like a 
honeycomb or network, completely eaten away by the 
teredo and other sea-worms. I have fully proved the 
efficiency of this method at different harbours and docks. 
Sixteen years ago I had timber prepared with it, and in 
use on the shores of the Dee, and it is at the present 
moment perfectly sound. The pyrolignite of iron must 
be used of very pure quality ; the timber must be dry ; 
afterwards the oil of tar must be applied, and not on any 
account must it contain a particle of ammonia. The 
immense destruction on the coast of timber by the sea- 
worms, and the important fact that at the Chain Pier 
there are not twenty of the original piles remaining at 
the present time, is of itself sufficient to awaken anxiety." 

With regard to the opinion of foreigners on the subject 
of creosoting, we cannot do better than quote the report 
of the commission or committee (instituted in 1859) of 
the Eoyal Academy of Sciences, Holland, upon the means 



DTxY ROT IN TIMBER. 235 

of preserving wood from the teredo, publislied at Haarlem 
in 1866. It is as follows : 

*^To conclude, it results from experiments which the 
committee has directed during six consecutive years, that — 

" 1st. Coatings of any sort whatever applied to the 
surface of the timber in order to cover it with an envelop 
upon which the young te7*edo will not fasten offer a very 
insufficient protection; such an envelop soon becomes 
damaged, either by mechanical action, such as the friction 
of water or ice, or by the dissolving action of water ; and 
as soon as any point upon the surface of the wood is 
uncovered, however small it be, the teredoes of microscopic 
size penetrate into the interior of the wood, 

" Covering wood with plates of copper, or zinc, or flat- 
headed nails are expensive processes, and only defend the 
w^ood as long as they present a perfect and unbroken 
surface. 

"2nd. Impregnation with soluble metallic salts gene- 
rally considered poisonous to animals does not preserve 
the wood from the invasions of the teredo ; the failure of 
these salts is partly attributable to their being soaked out 
of the WQod by the dissolving action of the sea- water, partly 
also to the fact that some of these salts do not appear to 
be poisonous to the teredo. 

"3rd. Although we cannot venture to say that there 
may not be found in the colonies a wood that may resist 
the teredoy yet we may affirm that hardness of any timber 
is not an obstacle to the perforations of this mollusc. This 
has been proved by the ravages it has made on the Gaiac 
and Mamberklak woods. 



236 PREVENTION AND CURE OF 

" 4th. The only means which can be confidently regarded 
as a preservative against the ravages of the ieredo is the 
creosote oil ; nevertheless, in the employment of this agent 
great care should be taken regarding the quality of the 
oil, the degree of penetration, and the quality of the wood 
treated." 

These results of the experiments of the committee 
are confirmed by the experience of a large number of 
engineers of ponts et chaussees (bridges and causeways) 
in Holland, England, France, and Belgium. For example, 
very lately a Belgian engineer, M. Crepin, expressed 
himself as follows in his Eeport, dated 5th February, 
1864, upon experiments made at Ostend : 

^^The experiment now appears to us decisive, and we 
think we may conclude that fir timber well prepared with 
creosote oil of good quality is proof against the teredo, 
and certain to last for a long time. Everything depends, 
therefore, upon a good preparation with good creosote oil, 
and on the use of wood capable of injection. It appears 
that resinous wood is easiest to impregnate, and that white 
fir should be rejected." 

M. Forestier, the able French engineer at Napoleon- 
Vendee, sums up as follows the results of the experiments 
undertaken by him in the port of Sables-d'Olonne, viz. : 

'' These results fully confirm those obtained at Ostend, 
and it appears to us difficult not to admit that the experi- 
ments of Ostend and Sables d'Olonne are decisive, and 
prove in an incontestable manner that the teredo cannot 
attack wood properly creosoted." 

It thus appears that there are three preservative 



DRY ROT I"N TIMBER. 237 

methods, which, according to experience, will save timber 
piles from the ravages of the worms, viz. : 1st. By using 
woods able to resist unaided their attacks. 2nd. The me- 
chanical method, which is, by covering the piles with 
scupper nails, &c. This process is, however, very ex- 
pensive, especially as the four sides of the pile must be 
covered; and, moreover, it affords no protection to the 
timber from internal rot or decay. 3rd. The chemical, or 
" creosoting " method. This process is cheaper than the 
last ; it preserves the wood from decay, and no worms will 
touch it. 

When unprepared piles are placed in the sea, there is 
every probability, sooner or later, of their being attacked by 
the teredo. This animal, however, is not left in peaceable 
enjoyment of the dwelling which it has constructed, and 
the food which it loves, but is liable to be attacked by^ an 
enemy, an annelide, to which the late M. de Haan has 
given the name of Lycoris fucata. This animal is to be 
found wherever the teredo exists, indeed its eggs and 
larva are to be met with in the midst of those of the 
mollusc. M. Kater has remarked that the adult lycoris 
dwelling in the mud which it enters during winter, and 
into which the piles are driven, climbs up the pile to the 
hole formed by the teredo, where, in some manner, it 
sucks or eats its victim ; then having enlarged the 
entrance to the hole, it enters and rests in the place of 
the teredo. After a time it goes back to the entrance, 
and commences to seek for fresh prey. 

The lycoris is narrow and not very long, provided 
laterally with a great many little feet terminating in points 



238 PREVENTION AND CUBE OF 

and covered with hair, and having in front a pair of hard 
superior jaws, pointed horns, and the inferior jaws bent 
round in the form of hooks. Behind the head are four 
pairs of tubuliform gills. It is with these arms that this 
little animal pursues and devours the teredo. 

One day M. Kater was fortunately able to observe the 
operations of the lycoris. One of these animals coming 
out of a hole in the wood w^hich he inhabited, seized upon 
a teredo, which M. Kater had previously deposited at the 
bottom of the vessel containing the w^ood. He saw the 
annelide seize the teredo^ hurry away with it to the hole 
which he occupied, and so completely devour it that he 
finally left only the two valves of the shell. Our illustra- 
tions of the teredo and lycoris are derived from the works 
of Mr. Paton and M. Forestier ; and our own sketches. 

If the lycoris would only destroy the teredo^ when 
the mollusc was in its infancy, what an invaluable little 
annelide it would be ! 

It appears to us a great pity that the woods we have 
named, or some of them, are not brought over to England 
in large quantities for harbour works. In Ceylon and 
India, the trees are felled by Indian wood-cutters at little 
cost; they are then dragged to the river banks by 
elephants or buffaloes, to be floated down the rivers to 
the different ports, so that labour is cheap. The question 
then remains, how to get the woods to England ? When 
the ' Great Eastern ' ship has finished carrying cables, 
perhaps its owners will not object to send the ship on a 
few voyages with heavy cargoes to India, Demerara, &c., 
bringing home " teredo-proof woods," at moderate charges 
for freight ? 



DRY ROT IN TIMBER. 239 

Finally, to place the subject in a practical form, we 
think the Institute of Civil Engineers, of London, would 
be heartily thanked by the engineering world if they 
would appoint a committee to inquire into the damages 
done to works by sea-worms ; why they are found in some 
parts of a roadstead or harbour, and not in others ; to 
consider the different remedies which have been proposed, 
their cost, and method of application ; what^course should 
be adopted to prevent sea- water injuriously affecting iron 
piles ; and lastly, to publish a detailed account of their 
experiments and recommendations. 



240 pre^t:ntion and cure of 



CHAPTER YIII. 

ox THE DESTEUCTION OF WOODWORK IN HOT CLIMATES 
BY THE TERMITE OR WHITE ANT, WOOD-CUTTER, 
CARPENTER BEE, &c., AND THE MEANS OF PREVENTING 
THE SAME. 

Of the ant proper, or that belonging to the order Hymen- 
optera, there are three species * in particular which attack 
timber, viz. : 

1st. Formica fuliginosa^ or black carpenter ant, which 
selects hard and tough woods. 

2nd. Formica fusca^ or dusky ant, which prefers soft 
woods. 

3rd. Formica fiava, or yellow ant, which also prefers 
soft woods. 

The carpenter bee prefers particular kinds of wood. In 
India it is very fond of cadukai {Tamil) wood, which is 
often used for railway sleepers. Bound the holes it 
makes there is a black tinge, arising, probably, from the 
iron in its saliva acting on the gallic acid of the timber. 
Providing it meets with the wood it prefers, it is not very 
particular whether it is standing timber, or the beams of 
a residence. 

The termite, or white ant, is a terrible destroyer of wood 
in nearly all tropical countries. There are many species 

* See Hurst's ' Tredgold's Carpentry,' p. 380, 1871. London. 



DRY ROT IN TIMBER. 241 

of termite, and all are fearfully destructive, being indeed 
the greatest pest of the country wherein they reside. 
Nothing, unless cased in metal, can resist their jaws ; and 
they have been known to destroy the whole woodwork of 
a house in a single season. They always work in darkness, 
and, at all expenditure of labour, keep themselves under 
cover, so that their destructive labours are often completed 
before the least intimation has been given. For example, 
the termites will bore through the boards of a floor, drive 
their tunnels up the legs of the tables or chairs, and con- 
sume everything but a mere shell no thicker than paper, 
and yet leave everything apparently in a perfect condition. 
Many a person has only learned the real state of his furni- 
ture by finding a chair crumble into dust as he sat upon 
it, or a whole staircase fall to pieces as soon as a foot was 
set upon it. In some cases the termite lines its galleries 
with clay, which soon becomes as hard as stone, and thereby 
produces very remarkable architectural changes. For 
example, it has been found that a row of wooden columns 
in front of a house have been converted into a substance 
as hard as stone by these insects. In pulling down the old 
cathedral at Jamaica, some of the timbers of the roof, 
which were of hard wood, were eaten away, and a cartload 
of nests formed by the ants was removed, after being cut 
away by great labour with hatchets. 

The first indication of a house being attacked by ants 
in the tropics is, perhaps, the yielding of a floor board in 
the middle of a room, or the top hinge of a door suddenly 
leaving the frame to which it had been firmly screwed a 
short time before. 



242 PREVENTION AND CURE OF 

That the ants provide for winter — as not only Dr. Ban- 
croft and many others, even King Solomon, reports — is 
found to be an error. Where there is an ordinary winter, 
the ants lie dormant, during which torpid state they do 
not w^ant food. 

The greater number of species belong to the tropical 
regions, where they are useful in destroying the fallen 
trees that are so plentiful in those latitudes, and which, 
unless speedily removed, might be injurious to the young 
saplings by which they are replaced. Two species, how- 
ever, are known in Europe, namely, Termes lucifugiis and 
Termes rucifollis, and have fully carried out their de- 
structive character, the former species devouring oaks and 
firs, and the latter preferring olives and similar trees. At 
La Bochelle these insects have multiplied so greatly as 
to demand the public attention. 

M. de Quatrefages, who visited one of the spots in which 
these destructive insects had settled themselves, gives the 
following account of their devastating energy : '^ The 
prefecture and a few^ neighbouring houses are the prin- 
cipal scene of the destructive ravages of the termites, but 
here they have taken complete possession of the premises. 
In the garden not a stake can be put into the ground, and 
not a plank can be left on the beds, without being attacked 
within twenty-four or forty-eight hours. The fences put 
round the young trees are gnawed from the bottom, while 
the trees themselves are gutted to the very branches. 

'' Within the building itself the apartments and offices 
are all alike invaded. I saw upon the roof of a bedroom 
that had been lately repaired galleries made by the termites 



DRY ROT IN TIMBER. 243 

which looked like stalactites, and which had begun to 
show themselves the very day after the workmen left the 
place. In the ceHars I found similar galleries, which 
w^ere either half way between the ceiling and the floor, or 
running along the walls and extending, no doubt, up to 
the very garrets, for on the principal staircase other 
galleries were observed, between the ground floor and the 
second floor, passing under the plaster wherever it was 
sufficiently thick for the purpose, and only coming to view 
at different points where the stones were on the surface, 
for, like other species, the termites of La Eochelle always 
work under cover wherever it is possible for them to do 
so. It is generally only by incessant vigilance that we 
can trace the course of their devastations and prevent 
their ravages. 

'' At the time of M. Audoin's visit a curious proof was 
accidentally obtained of the mischief which this insect 
silently accomplishes. One day it was discovered that 
the archives of the department were almost totally de- 
stroyed, and that without the slightest external trace of any 
damage. The termites had reached the boxes in which 
these documents were preserved by mining the wains- 
coting, and they had then leisurely set to work to devour 
these administrative records, carefully respecting the 
upper sheets and the margin of each leaf, so that a box 
which was only filled by a mass of rubbish seemed to 
enclose a file of papers in perfect order. 

" The hardest woods are attacked in the same manner. I 
saw on one of the staircases an oak post, in which one of 
tlie clerks had buried his hand up to the wrist in grasping 

R 2 



244 PREVENTION AND CURE OF 

at it for support, as his foot accidentally slipped. The 
interior of the post was entirely formed of empty cells, the 
substance of which could be scraped away like dust, while 
the layer that had been left untouched by the termites was 
not thicker than a sheet of paper." 

It is most probable that these insects had been imported 
from some vessel, as they attacked two opposite ends 
of the same town, the centre being untouched. M. de 
Quatrefages tried many experiments on these insects with 
a view of discovering some method of destroying them, 
and came to the conclusion that if chlorine could be in- 
jected in [sufficient quantities, it would in [time have the 
desired result. 

The termite or white ant is represented by Linnaeus 
as the greatest pest of both Indies, because of the havoc 
they make in all buildings of wood, in utensils, and in 
furniture. They frequently construct nests within the 
roofs and other parts of houses, which they destroy if not 
speedily extirpated. The larger species enter under the 
foundations of houses, making their way through the floors 
and up the posts of buildings, destroying all before them ; 
and so little is seen of their operations that a well-painted 
building is sometimes found to be a mere shell, so thin 
that the woodwork may be punched through with the point 
of the finger. 

]\Iany kinds of wood in Brazil * are impervious to the 
termite, which insect generally selects the more porous 

* See Charlesworth's 'Magazine of Natural History/ 1838, Art. Myrmica 
domestica. Also, * Boston Journal of Natural History/ 1834, p. 993, Art. 
Myrmiea molesta. 



BBY ROT IN TIMBER. 245 

woods, and especially if these are in contact with the 
earth. In dry places, and with a free circulation of air, it 
does not prefer timber thus situated ; and it is found that 
roofs of buildings of good and well-seasoned native wood 
resist for an indefinite period both the climate and the 
termite. As a general rule, Brazilian timber is very 
brittle. 

It shows the difference of effects between one climate 
and another, that in Brazil the more porous and open- 
grained timbers are most subject to the attacks of the 
white ant, especially if they are in contact with the earth ; 
but in Australia it is the reverse, for there it is the hardest 
description of timber that those insects first attack. There 
is one wood in particular, in common use, to which this 
remark applies, namely, " Iron Bark." Its density is 
so great that it sinks in water, and its strength is extra- 
ordinary, and yet the wood the white ants are particularly 
fond of. In the West Indies, the ants prefer hard woods. 

At Bahia, the timber is less affected by the termite 
than in Pernamhu^o; but even in the latter place the 
white ant does not like dry places with a free circulation 
of air. 

Mr. Shields, when on a short visit to Pernambuco, 
examined some timber bridges, and in one, which had 
only been constructed three years, he found the ends of 
the timber had been placed in contact with the moist 
clay ; at those places he could readily knock off the crust 
of the wood, and the interior of the wood was almost 
filled with white ants : the decay was augmented by the 
contact of the wood with the moist clay. We have been 



246 PREVENTION AND CUKE OF 

informed that timber for the Government works is stored 
to the depth of about 1 foot 6 inches in the sea-sand, to 
protect it from the white ants and the teredo ; and that in 
Pernambnco, since the establishment of the gas-works, 
the Brazilian engineers and eonstrnctors " pay " over the 
ends of all timbers used in buildings with coal-tar. 

In Ceylon, no timber — except ebony and ironwood, 
which are too hard ; palmyra, in northern Ceylon ; and 
those which are strongly impregnated with camphor or 
aromatic oils, which they dislike — presents any obstacle 
to their ingress. Sir Emerson Tennant, in his work on 
Ceylon, says : '' I have had a cask of wine filled, in the 
course of two days, with almost solid clay, and only dis- 
covered the presence of the white ants by the bursting 
of the corks. I have had a portmanteau in my tent so 
peopled with them in the course of a single night that 
the contents were found worthless in the morning. In an 
incredibly short time a detachment of these pests will 
destroy a press full of records, reducing the paper to 
fragments; and a shelf of books will be tunnelled into 
a gallery, if it happened to be in their line of march." 

In Ceylon, the huts are plastered over with earth, 
which has been thrown up by white ants, after being 
mixed with a powerful binding substance (produced by 
the ants themselves), and through which the rain and 
moisture cannot penetrate. This will hold the walls 
together when the entire framework and the wattles 
have been eaten, or have become decayed. 

In the Philippine Islands, ambogues, a strong, durable 
wood, suffers much from the termites. Sir John Bowring> 



DRY ROT IN TIMBER. 24? 

in liis work on these islands, thus writes of the rava2:es of 
the white ants in the town of Obando, Province of Bulacan, 
Philippine Islands: *'It appears that on the ISth March, 
1838, the various objects destined for the services of the 
mass, such as robes, albs, amices, the garments of the 
priests, &c., were examined, and placed in a trunk made 
of the wood called ^ narra ' (Pteroearpus palidus). On the 
19th they w^ere used in the divine services, and in the 
evening were restored to the box. On the 20th some 
dirt was observed near it, and, on opening it, every frag- 
ment of the vestments and ornaments of every sort were 
found to have been reduced to dust, except the gold and 
silver lace, which were tarnished with a filthy deposit. On 
a thorough examination not an ant was found in any other 
part of the church, nor any vestige of the presence of these 
voracious destroyers ; but five days afterwards they were 
discovered to have penetrated through a beam 6 inches 
thick." 

The red ant in Batavia (north-west end of Java) is 
another devastator. The red ant contains formic acid 
(acid of ants) and a peculiar resinous oil. Thunberg* 
has found cajeput effectual in destroying the red ants of 
Batavia: he used it to preserve his boxes of specimens 
from them. When ants were placed in a box anointed 
w^ith this oil, they died in a few minutes. 

In Surinam, Guiana, several species of worms are pro- 
duced in the palm-trees as soon as they commence to rot : 
they are called " groo-groo," and are produced from the 
spawn of a black beetle ; they are very fat, and grow to 
* • Thunberg's Travels/ vol. ii. p. 300. 



248 PREVENTION AND CURE OF 

the size of a man's thumb. The groo-groo will very 
quickly destroy wood which has commenced to rot. 

In Surinam, Captain Stedman* was obliged to drive 
nails into the ceiling. of his room, and hang his provisions 
from the nails ; he then made a ring of dry chalk around 
them, very thick, which crumbled down the moment the 
ants attempted to pass it. In Guiana, the young ants will 
swim across a small pool of water to get at sugar ; some 
get drowned, the rest get the sugar. 

In Japan, according to Koempfer,t ants do considerable 
damage to wood. 

In Senegal, the ant (Termite helliqueux) is a formidable 
agent of destruction. In a season, all the carpentry of a 
house is destroyed by them. Spartmann, in his ' Voyage 
to the Cape of Good Hope,'J gives an excellent account of 
their methods of working. 

The Termite lueifuge has been discovered in the environs 
of Bordeaux, in the pine-trees ; also in the marine work- 
shops at Bochefort. It is believed to have been imported 
from America. 

The Termite flavicole, a few years since, attacked the 
olive-trees of Spain, and it occasionally visits the centre 
of France, 

White or yellow pine wood can only be used in the 
tropics for doors, movable window frames, bodies of railway 
waggons, or other work intended to be kept in motion. 
Its use even for these purposes is questionable, as the 

♦ * Expedition to Surinam.' By Captain Stedman. 1813. London, 
t Kosmpfer's * Japan,' vol. ii. 

X * Voyage de Spartmann au cap de Bonne-Esperance : voy. Diet, d^Hist, 
iVa^. de Guerin.' 1839. 



DRY ROT IN TIMBER. 249 

white ant has such an affinity for it, that a door or a 
window which has remained shut for a few weeks will 
almost invariably be attacked by that insect. 

North American pitch pine withstands very well the 
attacks of the termite, when used in the roofs of buildings, 
or in any locality not humid ; but it is found after a 
time, when laid upon the earth, to lose its resisting 
powers, as well as to become subject to rapid decay. 

*^ Greenheart " timber in its natural state is proof 
against the attacks of this insect in tropical climates 
— especially that known as the "purple-heart" wood. 
There are two reasons why it enjoys this immunity from 
attack : first, there is its great hardness ; and, secondly, 
there is the presence of a large quantity of essential oil. 
It is very hard and durable wood ; a little heavier than 
water. It is obtained at Demerara.* Great care is re- 
quired in working it, as it is very liable to split. In 
sawing it is necessary to have all the logs bound tightly 
with chains, failing which precaution the log would break 
up into splinters, and be very apt to injure the men work- 
ins: it. 

'' Jarrah " wood, from Australia, is also proof against 
the attacks of the white ant. It is occasionally liable 
to shakes. 

"Panao" wood, from the Philippine Islands, gives the 
talav oil, which destrovs insects in wood. 

'^ Bilian " wood is imported to Bombay, from Sarawak, 

♦ See Paper by Mr. J. B. Hartley, read before tlie Institution of Civil 
Engineers, London, 23rd June, 1840, " On the Kffects of the ^Vorm on 
Kyanized Timber exposed to the Action of Sea Water ; and on the Use of 
Greenheart Timber from Demerara." 



250 PREVENTION AND CURE OF 

Borneo. This wood is impervious to the attacks of the 
termite, and does not decay when under fresh or salt 
water, where it remains as hard as stone. 

"Sal" wood, in India, is occasionally touched by the 
white ant. This wood, however, requires two years to 
season, and it will twist, shrink, and warp whenever the 
surface is removed, after many years' seasoning. Only 
about 2 lb. of creosote oil per cubic foot can be injected 
into sal wood. "Kara-marda" is avoided by this little 
insect; but wlien used for planks it requires twelve to 
fifteen months' previous seasoning. "Neem-wood," used 
for making carved images, enables an image to remain 
undisturbed by the white ant. 

The following is a list of woods which resist for a long 
time, if not altogether, the attacks of the termites, or white 
ants : 

ANT-RESISTING WOODS. 

America. — Butternut, pitch pine. (Pitch pine is sometimes attacked.) 

Australia^ Western, — Jarrah. 

Borneo, — Bilian. 

Brazil — The sicupira assii, sicupira meirim, or verdadeiro, sicupira acari, 
oiticira, gararoba, pao saulo, sapucaia de Pilao, sapucarana, pad ferro, and 
imberiba, resist the white ant, except in the sapwood. The angelim amar- 
gozo, araroba, pitia, cocao, bordao de Velha, ameira de Sertao, parohiba, 
cedro, louro cheiroso, and louro ti, resist the white ant, even in the 
sapwood. 

Ceylon. — Ebony, iron wood, palmyra, jack, gal-mendora, paloo, cohambe. 

Deinerara. — Greenheart. 

Guiana, British. — Determa, cabacalli, kakatilly. 

India. — Cedar, sal, neem, kara marda, sandal, erul, nux vomica, thet- 
gan, teak. (Ants wiU bore through teak to get at yeUow pine.) 

Indies, West. — Bullet wood, lignum vita?, quassia wood. 

Pernamhuco (^Brazil). — Magaranduba (red), barubii (purple), mangabevia 
de Viado. 

Philippine Islands. — Molave, panao. 

Tasmania. — Huon pine. 

Trinidad. — Sepe. 



DRY EOT IN TIMBER. 251 

In piles of wooden sleepers wliich have been lying ready 
for use in India for about six months, at least 10 per cent, 
have been found destroyed by ants. It has been supposed 
that tlie jarring motion of a train on a railway would 
prevent the white ant from destroying the timber sleepers ; 
but there is reason to doubt this, from the fact that on 
an examination of the * Hindostan ' steam vessel, a con- 
siderable portion of her timber framing was found to be 
eaten away by that destructive insect, particularly in the 
pai'ts close to the engine and boilers, where there had been 
the greatest amount of vibration. The telegraph posts are 
particularly subject to their depredations so long as the 
timber is sunk in the ground ; but when a metallic socket 
is supplied, the wood is safe from their visits. A further 
precaution is taken to preserve the lower end of the post 
by running liquid dammer into the metallic sheath, so 
that the enclosed part of the post is encased with a coating 
of resin. The telegraph wires when covered with gutta- 
percha (a vegetable substance) are also liable to their 
attacks. 

Numerous expedients have been suggested for getting 
rid of this destructive insect, some of which have been 
successful, but the majority only partially so. 

In India, the timbers of a house infested with white 
ants are periodically beaten to drive them away. Of 
course, this only succeeds for a short time, as they soon 
return. 

The salt vessels plying on the coast of India use oil of 
tar, and a considerable quantity of castor-oil, mixed with 
cow-dung mortar, which, while it adheres to the wood, is 



252 PREVENTION AND CURE OF 

an effectual protection against ants and rot. The earth 
oil, or Arracan oil, is considered as good as creosote to 
protect wood from ants. It can be obtained at Moulmein 
and Kangoon, in leathern bottles or skins, at about 6d. 
per gallon. 

It used to be a practice in the West Indies to destroy 
whole colonies of ants which had built their nests either on 
trees or under the roofs of houses, by shooting powdered 
arsenic out of a quill into an orifice made into their 
covered ways, along which they ascended and descended 
from and to the ground. 

It has been estimated that the depredations of the white 
ant in India costs the Indian Government 100,000?. a year, 
which is expended in repairing the woodwork of houses, 
barracks, bridges, &c. 

When Dr. Boucherie gave up his sulphate of copper 
process for the use of the French public, lie received a 
national reward. If the Indian Government is disposed to 
give us a national reward, we could show how it may save 
at least half the 100,000Z. a year — which is expended in 
repairing the damages done by the white ants — with little 
troul)le. 

In the Madras Presidency periodical inspections have to 
be made, not only with regard to the white ant, but with 
respect to the presence and subsequent germination of 
vegetable matter or seeds in the mortar. In some instances, 
where proper precautions had not been taken, roots had 
formed very rapidly, and of such great size as to bodily 
dislodge by their pressure large stones from buildings. 



BRI LOT IN TIMBER. 253 

Therefore, to prevent this germination, a proportion of 
'*Jagherry," or coarse native sugar, varying from 2 per 
cent, in ordinary work, to from 5 per cent, to 8 per cent 
in arch work, is mixed with the lime. 

In 1856, in consequence of tlie ravages of the white ants 
in the King's Magazine, Fort William, India, the flooring 
and powder racks had to be reinstated. Captain A. Fraser, 
K.E., had the basement covered with concrete, 4 lb. of 
yellow arsenic being added to every 100 cubic feet of 
concrete. In the mortar used for the pillars arsenic was 
used in the proportion of ^ lb. to every 100 cubic feet of 
brickwork ; a small quantity of arsenic was also mixed 
with the paint, and ^ lb. (four chittacks) of arsenic was 
also mixed with every 100 superficial feet of plaster. In 
1859 the town mayor reported to the Government that no 
traces of w^hite ants had since been found eitlier inside or 
outside the building. 

Colonel Scott, when Acting Chief Engineer, Madras 
Presidency, reported to the Government, December 24, 
1858, that the following receipt was used for exterminating 
white ants in the Madras Presidency, and was found to be 
very successful : 

lb. oz. 

Arsenic 2 4 

Aloes 2 4 

Chunam soap .. .. 2 13 (common country soap). 

Dbobiesmud .. .. 2 8 (Khar). 

Pound the arsenic and aloes, scrape the soap, mix with 
mud, and boil in a large chatty half full of water until it 
bubbles ; let it cool, and when cold, fill up with cold water. 
The mixture should boil for nearly an hour : it is applied 
as a wash. 



254 PREVENTION AND CURE OF 

The white ants of Calcutta are small in comparison 
with those of the upper provinces. 

Colonel Scott, Chief Engineer at Bombay, records 
instances of timber being boiled under pressure in various 
antiseptic solutions, such as sulpliate of copper, arsenious 
acid, and corrosive sublimate, with satisfactory results ; 
but considerable apparatus is necessary, and the expense 
forbids its use except in large public works. On the other 
hand, in 1817, Mr. Gr. Jackson, being engaged under 
Mr. Kendel, C.E., on works in India, tried several ex- 
periments with Mr. J. Bourne, in order to test the possi- 
bility of preserving timber from the ravages of the white 
ant. Ninety pieces of wood, 9 inches long by 4 inches 
square, saturated according to the different processes of 
Burnet, Payne, and Margary,* under the direction of the 
patentees themselves, were experimented upon, in five 
situations, one with a considerable amount of moisture, and 
four dry ; through inadvertency Mr. Bethell's specimens 
were only tested in the dry positions. The result was, 
that where there was moisture the timber was entirely 
destroyed, whilst where they were kept dry the result 
was better, but still not satisfactory. It seems difficult to 
account for these different results obtained bv Colonel 
Scott and Mr. Jackson; but evidently the same strength 
of solutions, and the same qualities and descriptions of 
woods, cannot have been used by each gentleman. 

Captain Mann and Captain McPherson painted the joists 
and planking of several buildings at Singapore with 

* Margary's process failed to preserve wood from rot on the Bristol and 
Exeter Kailway, England. 



DRY EOT IN TIMBER. ^ 255 

gamlir eomj)Ostt{on, and the result was perfect success, 
although the buildings had been previously infested with 
white ants. Gutta gambir is juice extracted from the 
leaves of a plant of the same name {TJncaria gamlir) 
growing in Sumatra, (fee, inspissated by decoction, strained, 
suffered to cool and harden, and then cut into cakes of 
different sizes, or formed into balls. Chief places of 
manufacture, Siak, Malacca, and Bittany ; gambir is now 
imported to England to a slight extent. The gambir 
composition referred to is made as follows : Dissolve 
three pints of gambir in twelve pints of daramer-oil over a 
slow fire ; then stir one part of lime, sprinkling it over the 
top to prevent its coagulating and settling in a mass at the 
bottom ; it must be well and quickly stirred. It should 
then be taken out of the cauldron, and ground down like 
paint on a muller till it is smooth, and afterwards returned 
to the pot and heated. A little oil should be added to 
make it tractable, and the composition can then l)e laid 
over the material. To be treated with a common brush. 
Against the Teredo navalis may be substituted the same 
proportion of black varnish or tar for dammer-oil, of 
course omitting the grinding down, which would not 
answer with tar. 

Burnett's chloride of zinc process is said to be a good 
preservative for wood liable to be attacked by ants : the 
zinc penetrates to the heart of the wood. 

Creosoted timber, it is well known, resists the attacks of 
the white ants ; but the close grain of the generality of 
tropical timber renders any attempt to creosote it all but 
useless. Of course, creosoted fir timber could be, in fact 



256 PREVENTION AND CURE OF 

is, exported from England, but the cost of freight and 
other charges will always make it very expensive, and be 
a great drawback to its general use abroad. Mre J. 0. 
Mellis, Engineer to the Government of St. Helena, whites 
in very high terms of creosoted timber as used there, 
where the white ant abounds. Between the years 1863 
and 1866, experiments * were made with many specimens 
of woods (by order of the Lieutenant-Governor), in order 
to find out those which would resist the white ant. Teak 
remained uninjured; jarrah wood was partially destroyed; 
while pitch-pine, oak, cedar, ash, elm, birch, beech, and 
mahogany, were quite destroyed. 

In Ceylon creosoted timber is not attacked by white 
ants, but the black coating, if exposed, renders it so heat- 
absorbing, that it is apt to split, and, unless thoroughly 
impregnated with the creosote, a road is opened to the 
inside, and the ants will soon destroy all that part which 
is unprotected. 

Coal-tar will destroy white ants. Some years ago 
Mr. Shields took short baulks of timber where the ants 
had commenced operations, and tried the system of 
pouring a very small stream of coal-tar through the heart 
of the timber which the ants had hollowed out, and after- 
wards splitting it open to see the result. He found the 
white ants completely destroyed ; they were shrivelled up 
like shreds of half-burnt paper by the mere effluvium of 
the coal-tar. 

♦ See Paper by Mr. Thomas Hounslow, of the Koyal Engineers' Depart- 
ment, publislied in ' Engineering/ p. 198, 21st September, 186G. Also, 
Hurst's edition of ' Tredgold's Carpentry,' page 380. 1871. London. 



DRY ROT IN TIMBER. 257 

Creosoting is excellent for railway sleepers, piles, &c., 
but it will not do for buildings, which the white ants 
prefer. It is objectionable for dwellings ; 1st, on account 
of its smell, which is disagreeable ; 2nd, on account of its 
colour, black, w^hich is unsightly ; 3rd, on account of its 
inflammability. 

With regard to the depredations of w^hite ants, anything 
of a bitter taste injected into the fibre of the wood prevents 
their attacks, though it may not be so good as coal-tar ; 
even a small quantity of turpentine has the effect of 
killing them instantly. Carbolic acid has been used, but 
its smell is objectionable. In South America, the leaves 
of the black walnut are soaked in water for some hours, 
then boiled ; and when the liquid has cooled, it is applied 
to the skins of horses and other animals, to prevent their 
being bitten or '' worried " by insects. We do not know if 
this has been used as a wash, or injected into wood, to 
prevent it being " worried " by ants. 

It thus appears that there is no remedy generally 
adopted in tropical climates for preventing the depreda- 
tions of the white ants ; but there is one method very 
frequently adopted in hot countries of getting rid of them. 
It is a desperate remedy, we admit, but desperate cases 
frequently require desperate remedies : it is simply by 
EATING THEM. Europeans have pronounced the termites 
to be peculiarly delicate and w^ell flavoured, something 
like sweetened cream. The termites are prepared for the 
table by various methods, some persons pounding them so 
as to form them into a kind of soft paste, while others 
roast them like coffee-beans or chestnuts. Termites, or 

s 



258 PREVENTION AND CURE OF 

white ants, are eaten by various African tribes, both raw 
and boiled ; and it is said that the Hottentots " get into 
good condition on this diet." In India, the natives capture 
great quantities of these insects, which they mix up with 
flour, producing a kind of pastry, which is purchased at a 
cheap rate by the poorer classes. In Ceylon, bears feed 
on the termites. Some of the Africans prepare large 
quantities of them for food, by parching them in kettles 
over a slow fire; in this condition they were eaten by 
handfuls as delicious food. The traveller Smeathman 
states that he often ate them dressed in this way, and 
found them to be '^delicate, nourishing, and wholesome, 
resembling in flavour sugared cream, or sweet-almond 
paste." In Brazil, the yellow ants are eaten by many 
persons. Humboldt states that in some of the South 
American countries ants are mixed with resin and eaten 
as a sauce. In Siam, ants' eggs are considered a luxury ; 
they are sent to the table curried, or rolled in green leaves 
mingled with fine slices or shreds of fat pork. In Sweden, 
ants are distilled along with rye to give a flavour to the 
inferior kinds of brandy. Chemists have ascertained that 
ants secrete a pleasant kind of vinegar, or a peculiar acid, 
called formic acid. 

In Brazil, however, the eating process goes on ex- 
tensively as follows : 

1st. Ants eat the wood. 

2nd. Ant-eaters eat the ants. 

3rd. Woodsmen eat the ant-eaters. 

4th. Wild animals eat the woodsmen. 

Teak-oil, extracted from teak chips, was, in 1857, re- 



DRY ROT IN TIMBER. 259 

commended by a Mr. Brown to the Government of St. 
Helena, through the Government of Madras. Timber 
coated with this oil, as reported to the Secretary to the 
Government of Madras by the several executive engineers 
of the Public Works Department, even when placed in a 
nest of white ants, was not touched by them. The cost 
of this oil, in certain experiments made by order of the 
Madras Government, in 1866, was reported to be 6J annas 
for IJ ounce, which is too expensive. In the central pro- 
vinces the cost would be IJ anna per quart.* 

In the East Indies there are several species of w^ood- 
cutter (Xylocopa) and carpenter bee (Xylocopa), which con- 
fine their ravages to the wood after it has been felled. 
The wood-cutter tunnels through the beams and posts 
of buildings, w^hich they frequent in great numbers. 
The passages are from 12 to 15 inches long, and more 
than half an inch in diameter. If the insects are nume- 
rous, their ravages are dangerously destructive, and they 
soon render beams unsafe for supporting the roof. 

The carpenter bee of Southern Africa is one of those 
curious insects which construct a series of cells in wood. 
After completing their burrow, which is open at each end, 
they close the bottom with a flooring of agglutinated saw^- 
dust, formed of the morsels bitten off during the operation 
of burrowing, lay an egg upon this floor, insert a quantity 
of " bee-bread," made of the pollen of flowers and their 
juices, and then cover the whole with a layer of the same 
substance that was used for the floor. Upon this is laid 
another egg, another supply of bee-bread is inserted, and 
* See Maconocliie's suggestion, p. 163. 

s 2 



260 PREVENTION AND CURE OF 

a fresli layer of sawdust superimposed. Each layer is 
therefore the floor of one cell and the ceiling of another, 
and the insect makes on the average about ten or twelve 
of these cells. 

The carpenter bee destroys the woodwork of buildings 
in the north of Ceylon, but in the south of the island 
woodwork has two enemies to contend against, viz. the 
porcupine and a little beetle. The porcupine destroys 
many of the young palm-trees, and the ravages of the 
cocoa-nut beetle {Longicornes) are painfully familiar to the 
cocoa-nut planters. The species of beetle, called by the 
Singalese " cooroominya," is very destructive to timbers. 
It also makes its way into the stems of the younger trees, 
and after perforating them in all directions, it forms a 
cocoon of the gnawed wood and sawdust, in which it 
reposes during its sleep as a pupa, till the arrival of the 
period when it emerges as a perfect beetle. Mr. Capper 
relates that in passing through several cocoa-nut planta- 
tions, " varying in extent from twenty to fifty acres, and 
about two to three years old, and in these I did not dis- 
cover a single young tree untouched by the cooroominya." 

Sir E. Tennant thus writes of the operations of the 
carpenter bee on the wooden columns of the Colonial 
Secretary's official residence, at Kandy, Ceylon: '^So 
soon as the day grew warm, these active creatures were at 
work perforating the wooden columns which supported the 
verandah. They poised themselves on their shining 
purple wings, as they made the first lodgment in the 
wood, enlivening the work with an uninterrupted hum of 
delight, which was audible to a considerable distance. 




Ccurpe'rvte^r Bees cut work. 



DRY ROT IN TIMBER. 201 

When the excavation had proceeded so far tliat the insect 
could descend into it, the music was suspended, but re- 
newed from time to time, as the little creature came to 
the orifice to throw out the chips, to rest, or to enjoy the 
fresh air. By degrees a mound of sawdust was formed at 
the base of the pillar, consisting of particles abraded by 
the mandibles of the bee ; and these, when the hollow was 
completed to the depth of several inches, were partially 
replaced in the excavation, after being agglutinated to 
form partitions between the eggs, as they are deposited 
within." 

Fortunately in England the owner of a house has no 
opportunity of watching ( " with an uninterrupted hum of 
delight, audible to a considerable distance " ) the opera- 
tions of the carpenter bee, on the wooden beams and posts 
of his building. 

We must now consider the ways of the wood-beetle, 
which will be found described in the next chapter, and 
only write a few words before closing this. A modern 
engineer is no sluggard, of that we are certain ; but if he 
intends erecting large buildings in any of the places 
abroad which we have referred to, he will find it very 
necessary to pay particular notice of the following words 
of King Solomon : 

'* Gro to the ant, thou sluggard ; consider Jier ways, and be wise." 

Proverbs vi. 6. 



262 PREVENTION AND CURE OF 



CHAPTER IX. 

ox THE CAUSES OF DECAY IN FUENITUEE, WOOD CAEV- 
INGS, ETC., AND THE MEANS OF PEEVENTING AND 
EEMEDYING THE EFFECT OF SUCH DECAY. 

Although trunks and boxes are of tliemselyes of little 
importance, they derive great consequence from the valu- 
able deposits of written papers, deeds, books, &c., which 
they frequently contain, that are subject to destruction 
from timber-destroying insects. It is well known that 
the smell of Russian leather, which arises from an essential 
oil, is a preservative of books. Leather or woods impreg- 
nated with petroleum, or with oil of coal-tar (which has a 
smell not much dissimilar) would be productive of the 
same effect, because known to be peculiarly obnoxious to 
insects : these oils are, however, very inflammable. 

At all times beech-wood is exposed to the attacks of 
beetles, and it cannot be used, even for household fur- 
niture, without being impregnated with some kind of oil 
or varnish, as a defence against these insects — a very 
curious fact, for the growing trees are remarkably free 
from the attacks of wood-devouring insects. Larch being 
solid, and its juices hot, pungent, and bitter, is rarely 
affected with the larvae of insects. 

Mr. Westwood, Hope Professor of Zoology, Oxford, 
says : '' The insects which in this country are found to be 



DRY ROT IN TIMEER. 263 

the most injurious from their habit of burrowing into the 
wood of furniture, belong to three species of beetles, of 
small size, and cylindrical in form (the better to enable 
them to work their way through the burrows in the wood), 
belonging to the family Ftinidse, and known under the 
systematic names of Ptiliniis jpectinieornis, Anobium stri- 
atum, and Anobium tessellatum, 

" In the perfect state, the insects of the genus Anobium 
are well known under the name of the " deathwatch," as 
these insects produce the ticking noise occasionally heard 
in old houses. It is also the Anobium striatum w4nch is so 
injurious in libraries ; the grub burrowing through entire 
volumes, and feeding upon the paper, and especially the 
pasted backs of the books. 

"The destruction of these insects, when enclosed in 
articles of furniture, is by no means easy, although with 
care much mischief might be prevented. The saturation 
of the wood with some obnoxious fluid previous to its 
being used up in the manufacture of objects of value 
would be beneficial. 

*' A strong infusion of colocynth and quassia, spirits of 
turpentine, expressed juice of green walnuts, and pyro- 
ligneous acid, have all been proposed. In hot climates 
the ravages of the Anobium on books have been prevented 
by washing their backs with a fluid compound of corrosive 
sublimate (ten grains) and four ounces of alcohol, and the 
paste used in the book covers is there also mixed with 
alcohol." 

Sir H. Davy and Professor Faraday hesitated to employ 
corrosive sublimate as a means of preventing the ravages 



264: PREVENTION AND CURE OF 

of the bookworm in Earl Spencer's library, at Althorp, 
not feeling certain as to whether the quantity of mercury 
used would affect the health of the inhabitants. Amongst 
all the combinations of mercury, perhaps the bi-chloride, 
or corrosive sublimate, is the most terrible poison. It 
should be remembered that there are two chlorides of 
mercury — one the proto-chloride, ordinarily known as 
calomel ; the other, bi-chloride, ordinarily known as cor- 
rosive sublimate ; the respective compositions of which 
are as follows : 



Calomel, and Corrosive Sublimate. 



Calomel, or proto-cbloride of mercury 
Corrosive sublimate, or bi-chloride of mercury 



Parts by Weight. 



Chlorine. Mercury 



36 
72 



200 
200 



Hence the ratio of chlorine in these two chlorides is as 
one to two. 

Botanists have long used a solution of corrosive subli- 
mate in alcohol, known by the name of Smith's solution, 
to preserve the specimens in their herbaria from the 
aggressions of insects. 

The Rev. J. Wood, writes:* "I know to my cost 
sundry Kaffir articles being absolutely riddled with the 
burrows of tliese tiny beetles {Anobium striatum), and not 
to be handled without pouring out a shower of yellow dust, 
caused by the ravages of the larva. The most complete 
wreck which they made was that of a New Guinea bow, 
which was channelled from end to end by them, and in 

* ' Insects Abroad.' By the Rev. J. Wood. 1874. London. 



DRY ROT IN TIMBER. 2G5 

many places they had left scarcely anything but a very 
thin shell of wood. 

" In such cases I have but one remedy, viz. injecting into 
the holes spirits of wine in which corrosive sublimate has 
been dissolved. This is not so tedious a business as it may 
seem to be, as the spirit will often find its way from one 
hole to another, so that if half a dozen holes be judiciously 
selected, the poison will penetrate the whole piece of wood, 
kill all the insect inhabitants, and render it for ever im- 
pervious to their attack. The above-mentioned bow cost 
me but little trouble. I first shook out the greater part 
of the yellow powder, and then, placing the bow perpen- 
dicularly, injected the spirit into several holes at the 
upper end. The effect was magical. The little beetles 
came out of the holes in all directions, and not one sur- 
vived the touch of the poisoned spirit ; many of them, 
indeed, dying before they could force themselves com- 
pletely out of the holes. The ticking of the deathwatch 
is, in fact, the call of the anobium to its mate, and as 
the insect is always found in old woods, it is very evident 
why the deathwatch is always heard in old houses. 
There is, by the way, a species of cockroach which acts 
in a similar manner, and generally disports itself on 
board ship, where the sailors know it by the name of 
' Drummer.' " 

The earliest account* we can find of the use of corrosive 
sublimate to destroy worms in woods is a few words men- 
tioned, in 1705, by M. Homberg, French Academian. In 

* ' Histoire de rAcademie/ p. 38. 1705. See also M. Maxime Paulet's 
communication to the Academy, 27tli April, 1874. 



266 PREVENTION AND CURE OF 

that year he stated that a person of position in Provence, 
France, knew how to make a parquet floor which would 
resist the worm, viz. by soaking the wood in water in 
which corrosive sublimate had been mixed, and this pro- 
cess ho had always found to be very successful. 

Herr Temmnick preserved his books from the anobium 
by dipping them in a solution of quassia. Except on a 
small scale, however, the saturation of furniture seems 
scarcely practicable. Fumigation seems, however, to be 
more available. For small objects, the practice adopted 
at the Bodleian Library, Oxford, on Professor Westwood's 
recommendation, appears good, viz. to enclose a number 
of volumes in a box, shutting quite close, and placing a 
small quantity of benzine in a saucer at the bottom of the 
case. The same plan might be adopted with small orna- 
mental wood- works, enclosing them in glass cases shut as 
nearly air-tight as possible. 

The Eeport of the Commission appointed by the De- 
partment of Science and Art to inquire into the causes 
of decay in wood carvings, and the means of preventing 
and remedying the effects of such decay, which was pub- 
lished in 1864, states that the action of the worm in wood 
carvings may be arrested, and the worm itself destroyed, 
by vaporization, more especially by the vapour of benzine ; 
and that, after the worm has been destroyed, further 
attacks from it can be prevented by treating the carved 
work with a solution of chloride of mercury, either in 
methylated spirits of wine, or parchment size, according 
to the surface character of the carving or wood- work ; the 
strength of the solution in each case being 60 grains of 



DRY ROT IN TIMBER. 267 

the chloride of mercury to a pint of fluid, whether spirits 
of wine or parchment size. The carving or wood-work 
shoukl be placed in a box, made as air-tight as possible, 
but with means of renewing the benzine placed in saucers 
from time to time as it evaporates without opening the lid 
of the box. Gilded carved work and panels on which 
pictures have been painted, and which have been attacked 
by the worm, can only be treated by applying the fumes 
of the benzine to the back of the pictures or gilded carved 
work : there is no reason to suppose that the vapour of the 
benzine would influence either the gilding of the one or 
the colours of the other. 

The process should always be carried out during the 
spring and early summer months, according to the state 
of the temperature and the observations of those in charge 
of the carved or other work, as to the action of the worm, 
which is manifested by the fine dust falling from the 
worm-holes, crevices, &c. 

Mr. Henry Grace was engaged in 1855 to restore some 
of the wood carvings in the Mercers' Hall, London, w^hich 
had been perfectly honeycombed by a small brown beetle 
about the size of a pin's head. The carvings being first 
washed, a number of holes w^ere bored in the back by a 
gimlet, and also into every projecting piece of fruit and 
leaves on the face. The whole was then placed in a long 
trough, 15 inches deep, and covered with a solution, pre- 
pared in the following manner : — 16 gallons of linseed oil, 
with 2 lbs. of litharge finely ground, 1 lb. of camphor, and 
2 lbs. of red lead, w^ere boiled for six hours, being, well 
stirred the whole time ; 6 lbs. of bees'-wax was then dis- 



268 PRETENTION AND CURE OF 

solved in a gallon of spirits of turpentine, and the whole 
mixed while warm thoroughly together. 

In this solution the carving remained for twenty-four 
hours. When taken out the face was kept downwards, 
that the oil in the holes might soak down to the face of 
the carving. The dust was allow^ed to remain to form a 
substance for the future support of the wood, and as it 
became saturated with the oil it increased in bulk, and 
rendered the carving perfectly solid. 

No insect has since been found to touch these carvings, 
as they could not subsist on this composition. 

In 1855 the carvings of Grinling Gibbons, at Belton 
House, were in such a condition as to render it absolutely 
necessary that something should be done to prevent their 
complete destruction. To this end they were placed in 
the hands of Sir. W. G. Eogers, who undertook to experi- 
ment upon their restoration. This gentleman reported 
that the first step he took was to have the various pieces 
photographed, as a means of recording the position of 
each detail of the ornamentation, &c. The whole of the 
w^orks were in a serious state of decay, portions being 
completely honeycombed by the worm. In order to 
destroy or prevent any future development of the insect 
within the wood, Mr. Eogers caused the whole to be 
saturated with a strong solution of corrosive sublimate 
(bi-chloride of mercury) in water. The colour of the wood, 
however, suffered so seriously by the action of the mer- 
cury that it was found necessary to adopt some means of 
restoring the original tint. (It gives a dark colour to 
the wood, which is caused by the metal contained in the 



DRY noT IN xnrBEE. 269 

sublimate.) This was effected by ammonia in the first 
instance, and subsequently by a sb'ght treatment with 
muriatic acid. After this the interior of the wood was 
injected with vegetable gum and gelatine, in order to 
fill up the worm-holes and strengthen the fabric of the 
carvings. A varnish of resin, dissolved in spirits of wine, 
was afterwards spread on the surface, and then the dis- 
membered pieces were put together in conformity with 
the photographs taken, as records, prior to the work of 
restoration having been commenced. 

In order to ascertain the present condition of these 
carvings, seven years after the operations detailed had 
been completed Mr. Rogers communicated witli the Hon 
Edward Gust, one of the trustees of the Earl Brownlow. 
who desired him to communicate with the clerk of the 
works at Belton. Mr. G. A. Lowe. Mr. Lowe, in writins: 
to Mr. Rogers, informed him that " there is never any 
appearance of worm dust from the very beautiful carving 
by Gibbons since you preserved it some years back." 

Mr. Rogers stated, at a meeting of the Royal Institute 
of British Architects, a few years since, that similar carv- 
ino^s at Ditton Park, Cashioburv, and Trinitv CoUe^xe, 
Oxford, are in a state of decay, the surface or skin, in 
some instances, being covered with a deceptive white 
vegetable bloom, which assists in completing the work of 
destruction. 

Painting hastens the work of destruction. In the 
library of Trinity College, Cambridge, some of the finest 
carvel work at some former time was thickly painted 
over, preventing the escape of the insects within, which 



270 PREVENTION AND CURE OF 

were compelled to feed on the last bit of woody fibre, 
leaving nothing but the skeleton of what it once was. At 
Cashiobury, where can be seen room after room of the 
finest of Gibbons' work, all this charming carving (about 
thirty years ago) was covered over and loaded with a 
thick brown paint and heavy varnish, destroying all the 
delicate feathering';of the birds and veining of the leafage, 
the repairs being done in plaster or a composition. 
Flowers, each about the size of an orange, were thus left 
with nothing but a skin of dust, with just enough fibre left 
to save them from collapsing in the handling. All the 
glorious work of Gibbons in the chapel of Trinity College, 
Oxford, was some years since covered with a dirty, un- 
drying oil. 

We dislike painters who paint carvings as much as the 

servant who applied to Mrs. H (wife of the celebrated 

landscape painter) for an " appointment " as cook, and 
having ascertained that the master of the house was a 
" painter," remarked, " I cannot take the situation, ma'am, 
as I have never lived in a tradesman's family.'' 

It is a difficult process to remove paint from carvings, 
as it is not possible to scour and wash it off in the ordinary 
way : it must be eaten off by an alkaline solution. 

With reference to the restoration of carvings which 
have not been painted, but only blackened by time, they 
must be scoured by the careful hand of an experienced 
man. 

Mr. Penrose, the present architect to the Dean and 
Chapter of St. Paul's, a short time ago examined the 4 
beautiful carvings in St. Paul's Cathedral, and he was 



DRY ROT IN TIMBER. 271 

able to state that they have not hitherto been attacked 
by worms. " Some portions had been broken by violence, 
but the state of preservation was marvellous." Mr. Kogers 
also observed that "he was greatly and agreeably sur- 
prised — contrary to his expectations — to find the carvings 
in St. Paul's in so good a state of preservatiou, and so 
free from the attacks of insects ; but such was undoubtedly 
the fact. How it was so he was not able to say." Why 
was this ? Well, Sir Christopher Wren was a wise man, 
and when he erected St. Paul's Cathedral, he engaged an 
experienced mason to remain at the Portland stone 
quarries, whose duty was to select every block of stone 
for the Cathedral, and when it arrived in London it was 
placed on Us natural led. The good results of this pre- 
caution can now be seen in the good preservation of the 
stone at the present time. If he was so careful of the 
stone for the walls, no doubt equal care was taken in 
the selection of the wood for carvings. Besides, the 
instructions* to the commissioners for rebuilding St. Paul's 
were drawn up with a view of preventing decay. The 
following is an extract from these instructions : 

" And to call to your Aid and Assistance such skilful 
Artists, Officers, and Workmen as ye shall think fit, and 
to appoint each of them his several Charge and Employ- 
ment ; to minister to such Artists and Officers, and to all 
and every other person and persons to be imployed in the 
said service, to whom you shall think meet, such Oath or 

* Their Majesties' Commission for the Rebuilding of the Cathedral 
Church of St. Paul, in London. London ; Printed by Benjamin Motte 
1692. 



272 PREVENTION AND CURE OF 

Oaths for the due performance of their several Duties, 
Employments, Offices, Charges and Trusts to them or any 
of them to be committed as shall by you be thought 
reasonable and convenient; and out of such Money as 
shall be received for this Work, to allow to them, and 
every of them, such Salaries, Wages, and Eewards respec- 
tively as to you shall seem fitting and proportionable to 
their Employment and the Service they shall do." * 

Sir Christopher Wren was descended from Dutch an- 
cestors : he was building for a Dutch king, and we there- 
fore perceive the reason why so much Dutch wainscot was 
introduced by him into England. 

It seems a great pity that the beautiful carvings of 
Grinling Gibbons and others should be allowed to go to 
decay for w^ant of proper attention. Why should this be ? 
We are acquainted with some of Gibbons' carvings, par- 
ticularly those in St. James's Church, Piccadilly, London ; 
but whether they are in a state of decay unknown to any 
one, whether any one looks after them, or whether it is 
" nobody's business" to do so, we cannot say. Every now 
and then the owner of some beautiful wooden carvings 
suddenly becomes acquainted with the fact that they are 
thoroughly riddled through by worms, and instead of having 
them looked after, they are pointed at as curiosities. 
Even the makers of " old furniture " take care that it 
shall be bored all over, to imitate the borings of worms. 

But what can be the cause of this decay? It must 
arise from one of two causes ; or, it may arise from both, 
viz. either tlie wood was not seasoned when fixed ; or else 
* Workmen would now think this clause a striking one. 



DRY ROT IN TIMBER. 273 

the quality and description of the wood for carving purposes 
was not attended to. There cannot be smoke without cause, 
and worms cannot exist unless a suitable habitation is 
first provided for them. Hard white oak is close grained, 
and will scarcely admit moisture ; whilst on the other 
hand the soft foxy-coloured oak from some parts of 
Lincolnshire, and other places, is so porous as to imbibe 
it easily and retain it ; and consequently is liable to early 
decay : in fine, the heart of this is scarcely equal to the 
sap of hard white oak. 

The English woods least liable to the worm for carvings 
are cedar, walnut, plane, and cypress; those most liable 
are beech, pear, alder, ash, birch, sycamore, and lime. 
All the fine carvings at Blenheim, Kidlington, and Wim- 
pole are in yelloiv deal, while in the age just before nothing 
but lime-tree and soft wainscot were used. The beautiful 
carvings of Gibbons, in the chapel of Trinity College, 
Oxford, are wrought in costly scented cedar and rich dark 
oak ; those in Trinity College, Cambridge, in white lime- 
tree wood. 

There is no doubt that wood to be used for carvins: 
should be hot, pungent, and bitter : thoroughly obnoxious 
to wood-destroying insects. If we cannot obtain this 
wood in England, we certainly can abroad, and one ship- 
load would last a long time for such purposes. Take, for 
instance, the Jarrah of Western Australia ; the Determa, 
the CahacalU, and Kakatilhj, of British Guiana; and the 
Sepe, of Trinidad : these woods are much valued where 
they grow, and no insects ever attack them. We do not 
say that they are suitable for wood carvings, but they 

T 



274 PREVENTION AND CURE OF 

might be tried, and we certainly know they are not likely 
to be worm-eaten at the end of a few years. They need not 
be discarded on account of their hardness; boxwood is 
hard, but some good carvings have been executed with 
boxwood. We can relate an anecdote about this wood. 
On 3rd June, 1867, Mr. W. G. Eogers, the celebrated 
wood-carver (would that he were alive now to read these 
words), was asked, at the Koyal Institute of British Archi- 
tects, if boxwood is objectionable for wood carvings,* and 
he did not reply to the question ; if he had given his 
opinion it would have been a valuable one, coming from 
such an authority. We must therefore get Mr. Eogers' 
opinion of this wood in another way. If the reader will 
refer to the " Eeports by the Juries," English Exhibition, 
1851, vol. ii., page 1555, he will find the following words : 

^^W. G. Eogers, of London. — A cradle executed in 
boxwood for Her Majesty Queen Victoria, and richly 
ornamented with carved reliefs ; also, a group of musical 
instruments, among which may be especially noticed a 
violin. These works show an extraordinary dexterity in 
the treatment of the material, and the ornaments of the 
cradle are in excellent taste. Prize medal." 

We have already referred to the Eeport of the Com- 
mission on the Decay of Wood Carvings, and as this 
report is now rather difficult to be obtained, we propose 
condensing some extracts from it, which may prove of 
value to the reader. 

* See lecture by Mr. W^. G. Eogers, ''On the Carvings of Grinling 
Gibbons," delivered at the Eoyal Institute of British Architects, 3rd June, 
1867. 



DBY ROT IN TIMBER. 275 

Of the tliree species of beetles injurious to furniture 
and carved work, the first, Ftilinus jpedinicorius is about 
one-fourth of an inch in length, and the male is dis- 
tinguished by its beautiful branched antennae ; the second, 
Anobium striatum^ which is by far the commonest and 
most destructive, is about one-eighth of an inch long and 
of a brown colour, with rows of small dots down the back ; 
and the third, Anobium tessellatwn, is about one-third to 
one-fourth of an inch long, the back varied with lighter 
and darker shades of brown scales. 

These insects are produced from eggs deposited by the 
females in crevices of the woodwork, from which are 
hatched small white fleshy grubs resembling the grubs of 
the cockchafer in miniature, which generally lie curled 
upon their sides, making very little use of their six small 
feet fixed near the head ; it is in this state that the insect 
is chiefly injurious, although the perfect insect itself also 
feeds on the wood. These grubs make their burrows 
generally in the direction of the fibre of the wood ; but 
when it becomes thoroughly dry and old, they burrow in 
all directions. 

When full grown they cease eating, cast ofi* their larva 
skins, and appear as inactive chrysalids with all the limbs 
lying upon the breast inclosed in little sheaths : after a 
short time the perfect insect bursts forth. 

The appearance of the insects in the perfect state takes 
place uniformly during the first hot days at the beginning 
of summer. Where they take a liking to a piece of wood- 
work, they seem to devour every particle of it, and as the 
perfect insects possess large wings beneath their hard wing 

T 2 



276 PREVENTION AND CURE OP 

sheaths, they are often seen flying in the hot sunshine out 
of doors, evidently in search of suitable woodwork for 
themselves and their progeny. 

Experiments were made by Mr. G. Wallis, Secretary to 
the Commission, with a view of ascertaining the best 
means of stopping the decay when commenced. The 
course pursued, as well as the results arrived at, will be 
best illustrated by a summary of Mr. Wallis's report on 
the subject. 

The experiments may be placed under two heads, viz. 
Vaporization and Saturation. 

I. Vaporization. 

At the end of April, 1863, when, from the appearance 
of certain specimens of carved work, the worm appeared 
to be developed and active, a large glass case, made as 
air-tight as circumstances would permit, was filled with 
examples of furniture, &c. 

The bottom of this case was covered with white paper, 
and the specimens of woodwork were raised above the 
surface by placing blocks of wood at convenient points. 
This insured the free circulation of the vapour over the 
whole surface of the objects. A dozen small saucers, with 
pieces of sponge saturated with carbolic acid, were dis- 
tributed about the bottom of the case. 

The raising of the objects on blocks of wood facili- 
tated the placing of these saucers at any desirable 
point. 

The carbolic acid was, in this experiment, renewed 



DRY ROT IN TIMBER. 277 

every three or four days for a month, and a strong vapour 
pervaded the case for that period, daring which there was 
no appearance of worms, dead or alive. At the end of 
May the saucers were removed, and the doors of the case 
thrown open, so that it might be well ventilated and 
cleared of vapour, after which it was closed again ; but 
the saucers were not replaced. This closing of the case 
without using the vapour was to prevent the escape of any 
beetles which might make their appearance, in the event 
of the vapour of the creosote not having destroyed the 
worms. About the middle of June, a fortnight after the 
case was closed again, beetles were seen crawling upon the 
white paper with which the bottom was covered. These 
beetles would, no doubt, deposit their ova in the usual 
course, as they could not escape, and a considerable 
number of them were found dead upon the white paper 
with which tlie surface underneath the carved work was 
covered. 

In order to test the efficacy of chloroform and benzine, 
two small glass cases, as nearly air-tight as possible, were 
selected, in which were arranged early in May specimens 
of ornamental woodwork, all more or less in bad con- 
dition from the worm. The bottom of each, as in the 
previous experiments, was covered with white paper ; and 
the objects to be acted upon raised upon small blocks of 
wood. In one case chloroform was used, and in the other 
benzine in a similar manner to the carbolic acid, i. e. by 
placing small pieces of sponge in saucers and saturating 
them with the liquid, using five saucers in each case. 
Both the chloroform and the benzine had to be renewed 



278 PREVENTION AND CURE OF 

mucli oftener than the carbolic acid, as the liquid evapo- 
rated much quicker. 

Within a week after the experiment commenced it was 
evident that the action of the chloroform had destroyed the 
worms as they came to maturity, and in a fortnight all 
the specimens of carved work having been taken from the 
case, and the dust produced by the action of the worms 
shaken out, a number of dead ones were found, as also 
some dead beetles ; but these were evidently those of past 
seasons remaining in the crevices of the woodwork. 

On examining the specimens of carved work placed in 
the case treated with benzine, there was no appearance of 
worms or beetles dead or alive. 

The two cases, with their contents, were then kept open 
for a week, and thoroughly ventilated to clear them 
as far as possible of all fumes of either chloroform or 
benzine. 

After this they were closed again, being then free from 
all traces of vapour, and were not opened for some 
months. Throughout the summer, the temperature being 
the same as that under which beetles appeared in the case 
treated with carbolic acid, no traces of worms or insects 
were visible, nor could the remains of any be discovered 
on the white paper, with which the lower surface of each 
case was covered. 

It would appear then, as far as vaporization is con- 
cerned, that the action of the vapour of carbolic acid is 
not sufficient ; in fact, it is sluggish and heavy, whilst 
chloroform and benzine are volatile and penetrating. The 



DRY ROT IN TIMBER. 279 

experiment with chloroform appears to prove that the 
vapour kills the worm, and, as no beetles appeared in the 
case during the summer, it may be inferred that it killed 
all the worms within its influence. 

From the pungency and penetrative action of the 
benzine, as also its volatile character and the fact that no 
life in the form of either worm or beetle was manifested 
in the case in which it was used, it seems fair to infer that 
it is more effective than even the chloroform. 

Vaporization on a large scale might be adopted by 
having a room made as air-tight as possible, stoj)ping up 
the chimney, pasting the window frames, &c., and placing 
infected furniture in the room, burning brimstone, or filling 
the room with fumes of prussic acid, chloroform, or benzine. 
It would have to be practised at the time when the perfect 
beetles made their appearance ; their destruction at that 
time involving, of course, the prevention of further injury 
by their progeny. 

II. Saturation. 

The experiments made with bi-chloride of mercury 
(corrosive sublimate) and methylated spirits of wine were 
not so successful as by vaporization, on account of the 
woodwork when dry (after having been saturated with the 
solution) having a varnished appearance. 

No experiment as to the effect of saturation in a 
solution of corrosive sublimate in water was made : 1st, 
because of the great risk to delicate carvings or pieces of 
furniture by their immersion in water, or the bringing up 



280 PREVENTION AND CURE OF 

of the grain of the wood by treatment with a brush ; and 
2nd, because the vaporization by benzine appeared to be 
quite sufificient to destroy the larvee. 

Before terminating this chapter, we trust a few words 
about carvers and carvings will not be out of place. 

There are two kinds of carvers, the house carvers and 
the shijo carvers; the former are used to flat and square 
surfaces, the latter to the rake or fay, as was the old 
term. 

About the period of Louis XIV. Malines was remark- 
able for its wood carvers, and the inhabitants might be 
seen sitting at their doors in the streets, plying their art 
in the same manner as now in many of the German and 
Swiss towns. Many works of art and decoration of 
Flemish origin are still preserved in England;* the 
works of Flemish carvers in wood were in great esteem, 
and there are numerous fine examples in the churches 
of Norfolk^ and other parts of England which may be 
regarded as their productions. Evelyn remarked that 
Gibbons came from the Low Countries. 

Grinling Gibbons created a school of carvers in Eng- 
land, and adopted a style and manner in building up his 
fruit and flowers to produce a grand effect. He chose 
but very few varieties of these out of his own garden, and 
it is wonderful how he varied and played with those few. 
He originated a peculiar description of light interlacing 

* Paper by M. de Laperier, of the Belgian Legation, read at a 
meeting of the Society of Antiquaries, relative to Flemish origin of 
English carving. 



DRY ROT IN TIMBER. 281 

scroll-work, which is to be met with in his best works ; 
no one has successfully attempted to carry it on since his 
time. There are several examples at Belton, and in the 
chapel and state rooms at Chatsworth, in the fine trophies 
at Kirthington Park ; but the upper part of the reredos 
of St. James's, Piccadilly, is a marvellous specimen."* 
The horizontal bands on the great organ in St. Paul's 
Cathedral are the perfection of this character of foliated 
scroU-work.f 

Gibbons' carvings have a loose freedom about them. 
At Chatsworth he educated his workmen, who partook of 
his inspiration. There is a great deal of his work scat- 
tered over the rooms, great hall, and staircase of Lyme 
Hall, near Disley, which was erected under the direction 
of Sir C. Wren. It was executed by the persons who 
were employed at Chatsworth, and took nine years to 
complete. 

At Blenheim there are some fine specimens of Chippen- 
dale's work, but what it all means is a mystery. Such a 
mixture of scraggy birds, and flowers cut into shreds, 
pagodas, and rustic waterfalls — all this fine workmanship 
employed to produce nothing but an incongruous whole 
of absurd objects. There is a leading line in all these 
works, indicating what the old carvers used to call the C 
and G style ; because if you attempt to draw it, it will 
resolve itself into these two letters. There is also the 
S and G style. 

* The large pulpit is not from the design of Sir Christopher Wren, nor 
is the carving by Grinling Gibbons, 
t See engraving in the 'Art Journal,' ISG6. 



282 PREVENTION AND CURE OF 

Abolish painting and we shall again have some fine 
house carvers. 

We have already given the conclusions at which the 
Commission appointed by the Department of Science and 
Art arrived, as to the prevention of decay or attack by 
these insects, and will now conclude this chapter by 
quoting Dean Swift's recipe for getting rid of the Anobium 
or Death watch : — 

" But a kettle of scalding hot water injected, 
Infallibly cures the timber affected ; 
The omen is broken, the danger is over, 
The maggot will die, the sick will recover." 



DRY ROT IN TIMBER. 283 



CHAPTER X. 

SUMMARY OF CURATIVE PROCESSES. 

The following summary of the most approved formula 
for preventing and curing the evils of rot is prepared 
from the works of Tredgold and Wylson ; some other 
more modern receipts have been added from ' The 
Builder/ ^Architect/ 'Building News/ and other pro- 
fessional periodical publications. Discretion in their use 
is recommended, and in serious cases we decidedly recom- 
mend consulting a professional man who is well acquainted 
with the subject. 

TO PRESERVE WOODWORKS THAT ARE EXPOSED TO 
WET OR DAMP. 

1. For those of an extensive nature, such as bridges, 
&c. The Hollanders use for the preservation of their 
sluices and floodgates, drawbridges, and other huge beams 
of timber exposed to the sun and constant changes of the 
atmosphere, a certain mixture of pitch and tar, upon 
which they strew small pieces of shell broken finely — 
almost to a powder — and mixed with sea-sand, and the 
scales of iron, small and sifted, which incrusts and pre- 
serves it effectually. 

2. A paint composed of sub-sulphate of iron (the 



2S4 PREVENTION AND CUBE OF 

refuse of the copperas pans), ground up with any common 
oil, and thinned with coal-tar oil, having a little pitch 
dissolved in it, is flexible, and impervious to moisture. 

3. Linseed oil and tar, in equal parts, well boiled 
together, and used while boiling, rubbed plentifully over 
the work while hot, after being scorched all over by wood 
burnt under it, strikes half an inch or more into the 
wood, closes the pores, and makes it hard and durable 
either under or out of water. 

4. For fences, and similar works, a coating of coal-tar, 
sanded over ; or, boil together one gallon of coal-tar and 
21 lb. of white copperas, and lay it on hot. 

TO PREVENT ROT. 

1. Thoroughly season the wood before fixing, and when 
fixed, have a proper ventilation all round it. 

2. Charring, after seasoning, will fortify timber against 
infection, so will a coating of coal-tar. 

TO CURE INCIPIENT DRY ROT. 

1. If very much infected, remove the timber, and 
replace with new. 

2. A pure solution of corrosive sublimate in water, in 
the proportion of an ounce to a gallon, used hot, is con- 
sidered a very effectual wash. 

3. A solution of sulphate of copper, half a pound to 
the gallon of water, laid on hot. 

4. A strong solution of sulphate of iron ; this is not so 
good as sulphate of copper. 

5. A strong solution of sulphates of iron and copper in 



DRY ROT IN TIMBER. 285 

equal parts, half a pound of the sulphates to one and a 
half gallon of water. 

6. Paraffin oil, the commonest and cheapest naphtha and 
oil, or a little resinous matter dissolved and mixed with 
oil, will stay the wet rot. 

7. Remove the parts affected, and wash with dilute 
sulphuric acid the remaining woodwork. 

8. Dissolve one pound of sulphate of copper in one 
gallon of boiling water, then add IJ lb. of sulphuric acid 
in six gallons of water, and apply hot. 

TO PREVENT WORMS IN TIMBER. 

1. Anointing with an oil produced by the immersion of 
sulphur in aquafortis (nitric acid) distilled to dryness, 
and exposed to dissolve in the air. 

2. Soaking in an infusion of quassia renders the wood 
bitter. 

3. Creosoting timber, if the smell is not objectionable. 

4. Anointing the timber with oil of spike, juniper, or 
turpentine, is efficacious in some degree. 

5. For small articles, cover freely with copal varnish in 
linseed oil. 

TO PREVENT W^ORMS IN MARINE BUILDING. 

1. A mixture of lime, sulphur, and colocynth with 
pitch. 

2. Saturating the pores with coal-tar, either alone or 
after a solution of corrosive sublimate has been soaked 
and dried into the wood. 

3. Sheathing with thin copper over tarred felt is 



286 PREVENTION AND CURE OF 

esteemed the best protection for the bottoms of ships 
\ ^^ for all marine animals ; the joints should be stopped with 
^ • \ tarred oakum. 

4. Studding the parts under water with short broad- 
headed nails. 

TO DESTROY WORMS IN CARVINGS. 

1. Fumigate the wood with benzine. 

2. Saturate the wood with a strong solution of corrosive 
sublimate : if used for carvings, the colour should be 
restored by ammonia, and then by a weak solution of hy- 
drochloric acid ; the holes may be stopped up with gum 
and gelatine, and a varnish of resin dissolved in spirits of 
wine should afterwards be applied to the surface. 

3. Whale-oil and poisonous ointments have been found 
of service. 

The wood should be carefully brushed before being 
operated upon. 

TO DESTROY ANTS AND INSECTS IN WOOD. 

1. Corrosive sublimate is an effectual poison to them. 

2. Oils, especially essential oils, are good preventives. 

3. Cajeput-oil has been proved effectual for destroying 
the red ant. 

4. Payne's, Bethell's, and Burnett's processes are said to 
be proof against the white ant of India. 

5. Dust the parts with pounded quicklime, and then 
water them with the ammoniacal liquor of gas-works, 
when the ammonia will be instantly disengaged by the 
quick-lime, and this is destructive to insect life. 



DRY ROT IN TIMBER. 287 

6. For the black ant, use powdered borax ; or smear the 
parts frequented by them with petroleum oil ; or syringe 
their nests with fluoric acid or spirits of tar, to be done 
with a leaden syringe; or pour down the holes boiling 
water to destroy their nests, and then stop up the holes 
with cement. Ants dislike arsenic, camphor, and creosote. 

The preceding remedies are not by any means given 
with the intention of superseding the previous chapters, 
which should be carefully studied by those who wish to 
acquire a moderate knowledge of the subjects. 



288 PREVENTION AND CURE OF 



CHAPTER XL 

GENERAL REMARKS AND CONCLUSION. 

Our task is nearly completed : we have but few general 
remarks to make. 

The decay of wooden sleepers, posts, &c., on our rail- 
ways and the destruction of timber piles by worms have 
been the causes of directing the attention of engineers to 
the preservation of timber. Most of our leading engineers 
now have the greater portion of the timber used in their 
works either creosoted or injected with chloride of zinc. 
Architects, as a rule, do not, unfortunately, adopt any 
process for preserving timber from rot and decay; and 
have practically no guarantee that timber used in 
their works has been thoroughly seasoned : posterity will 
not thank them for this, and yet they are not solely to 
blame. The fault in a great measure rests with the 
public, who require buildings to be erected at the least 
cost and in the shortest possible time. Moreover, the 
works executed by our leading builders are so extensive, 
that they have no room in their yards for large piles of 
timber to lie and season ; and even if they had room it is 
doubtful if they would allow so much material, represent- 
ing money, to remain idle. We are acquainted with one 
instance where a London architect, about a dozen years 
ago, erected a public building. The front of the reporters' 



DRY ROT IN TIMBER. 289 

gallery was formed of oak panelling ; and within a year 
after the completion of the building narrow slips or 
tongues of wood had to be let in in several places to fill 
up the holes formed by the shrinkage of the panels. 
Similar cases to this are by no means rare. AVe can quote 
another instance of unseasoned wood. A range of work- 
shops was erected a few years since in South London ; 
the principals of the roof were not ceiled ; almost before 
the building was finished the upper floor was occupied by 
a battalion of workwomen. The heat of the room (the 
ventilation being defective) soon had an effect upon the 
tie-beams, but one beam, which we imagine was un- 
seasoned, in consequence of large shakes and splits, had 
to be taken out and replaced with new. We will (as 
a lawyer would say) cite one more case. A church in 
Surrey required some extensive repairs to the roof: an 
architect and a builder were employed, and the necessary 
works were done. Within four years dry rot has made its 
appearance on the new timbers of the roof (not an air- 
tight one). One of the churchwardens, on consulting us 
last year (1874) as to the best means of stopping the rot, 
energetically remarked, '' Who is responsible to us for this, 
the architect or the builder?" Charles Dickens, in his 
edition of ' Bleak House ' in 1868, wrote, with reference 
to long Chancery suits, " If I wanted other authorities for 
Jarndyce and Jarndyce, I could rain them on these 
pages." We are able to make a similar remark with 
reference to any more instances of dry rot. Accordino- to 
the 7th chapter of the First Book of Kings, " Solomon 
was building his own house thirteen years : " wo cannot 

u 



290 PREVENTION AND CURE OF 

spare so much time novv-a-days over the erection of a 
house, but that is no reason why our timber should not 
be naturally or artificially seasoned. 

If we cannot obtain naturally seasoned timber, by 
all means let us have artificially seasoned wood. Tred- 
gold, in his Eeport on Langton's system,* nearly arrived 
at the secret. We will quote a few words from his 
Eeport : 

"Mr. Langton having discovered a new method of 
seasoning timber .... by which the time necessary to 
season green timber, and render it fit for use, is only 
about twice as many weeks as the ordinary process re- 
quires years ; .... it is more economical, and locks up 
less capital than the common method." 

We believe we may say that the number of our public 
buildings which have been erected during the present 
century with artificially prepared timber can be counted 
on our eight fingers (without troubling our thumbs) and 
not exceed that number ; f and yet we hear of dry rot in 
the great dome of the Bank of England and other build- 
ings without profiting by the events. We should like to 
know if the wooden dome of St. Paul's Cathedral is safe 
from dry rot, (the domes at the Pantheon and the Halle- 
au-Ble at Paris were affected,) and jplumhers fires. 

It is evident that a preservative process, thoroughly 
suitable for everyday use and applicable to buildings, 

♦ See Tredgold's Eeport on this process, May 2, 1828. 

t See Bartholomew's * Specifications,' and Professor Donaldson's valuable 
work on * Specifications,' which comprises many examples by modem 
architects. The usual clause is : '* The timber to be well seasoned (is 
it ?), free from large knots, shakes, and other defects." 



DRY ROT IN TniBER. 291 

has yet to be invented : it should be cheap, should render 
wood uninflammable, should preserve the wood from 
decay and dry rot, should not harden the wood until some 
time after its application, and should be colourless and 
invisible. The invention of such a process will require 
careful thought and experiments, for it appears to us that 
the whole theory of any successful plan for the preven- 
tion of the dry rot must resolve itself into the solidifying! 
or coagulation of albumen : this means hardening the 
sap-wood, and causing increased difficulty in working the 
wood. We can easily illustrate our remarks, by quoting 
one of the latest patents for preserving timber, which has 
recently been made public. It is the invention of a 
gentleman living in England, who has discovered a means 
of making wood uninflammable, preventing dry rot and 
decay, and rendering white and yellow pine, both in hard- 
ness and appearance, like teak and oak. We have no 
objection to its rendering wood uninflammable, providiQg 
it does not '' hurt " the wood ; but can the reader believe 
that any architect, in erecting a moderate-sized villa, 
would specify that all the joiners' work, staircases, window- 
frames and sashes, architraves, skirtings, doors, &c., must 
be formed of wood as hard as teaJc ; or rather, can the 
reader imagine the architect's client would be agreeable 
to pay the greatly increased cost for the extra labour 
involved. We do not think this invention will ever be 
used, at least to any extent, in buildings. 

Much yet remains to be done with regard to uninflam- 
mable wood for buildings : we think the matter should be 
dealt with (with reference to joists, floor boards, partitions, 

u 2 



292 PREVENTION AND CURE OF 

doors, staircases, roof timbers, &c.) by a new Buildings 
Act of Parliament. Stone and iron will not burn, but 
they are not fire-resisting : brick, artificial stone, and in- 
combustible wood will give us all we desire ; the details 
may be difficult of arrangement, but builders would 
comply with them if they were imperatively required. 
At present our houses are formed of brick walls, every 
room being separated vertically and horizontally from the 
adjoining rooms by combustible wooden walls. A street 
built up of fire-proof buildings would be a novelty. The 
whole subject requires to be dealt with thoroughly, for 
while we have combustible wooden floors, partitions, &c., 
we cannot at the same time have a fire-proof building. 
We have not been able to spare the space, or else we 
should have devoted a long chapter to this subject; a 
superficial consideration (such as alum and water) would 
have been practically useless. 

In conclusion, we can only summarize our remarks on 
the cause of dry rot, by saying, " Season and ventilate," 
in every case : as to the cure, that is not so easy to deal 
with. If the reader has ever had a decayed tooth aching, 
a friend has probably said, ^'Have it out;" and we 
say, wherever there is a piece of timber decayed in a 
building which can be removed, '• Have it out, and stop 
up with new ;" and in so advising we are merely following 
the advice to be found in a good old volume, which has 
never yet been equalled, and which says : 

" And, behold, if the plague be in the walls of the house with hollow 
strakes, greenish or reddish, which in sight are lower than the wall ; . . . . 
Then the priest shall command that they take away the stones in which 



DRY ROT IN TIMBER. 293 

the plague is, and they shall cast them into an unclean place without the 
city : And ho shall cause the house to be scraped within round about, and 
they shall pour out the dust that they scrape off without the city into an 
unclean place : And they shall take other stones, and put them in the 
place of those stones ; and he shall take other mortar, and shall plaister 
the house/' — Leviticus xiv. 37, 40, 41, and 42. 

This course will not, however, suit every ease, for when 
the rot has spread in many directions, the best and cheapest 
course is to consult some professional man, well versed in 
the peculiarities of dry rot, before determining upon any 
remedy, for w^e have shown in tlie course of this work that 
the disease may arise from various causes ; and it is not 
a difiScult matter to select the wrong remedy, and thus 
increase the disease. 

We trust the reader has found in this volume at least 

some hints which may be of service to him. A new house 

affected with dry rot is an unhealthy one to live in, and 

an old one is worse than the new ; we mean the kind of 

house referred to in one line by an American poet, as 

follows : 

" O'er whose unsteady floor, that sways and bends." 

Longfellow. 



[Index. 



INDEX. 



PAGE 



Abel's silicate of soda process IGO 

Academy of Sciences, Holland, report on seji- worms 235 

Acetate of lead 226 

„ iron and wood tar ] 30 

Acid, carbolic 257, 276 

,, fluoric 287 

„ hydrochloric 286 

„ hydro-fluo-silicic, and other substances 1G6 

„ nitric 98, 285 

„ pyroligneous Ill, 144, 263 

„ sulphuric .. IGl, 285 

„ vegetable Ill 

Age of trees, how to ascertain 9 

Air, admission of, to prevent or cure rot .. .. 27, 171, 187, 284, 292 

Albert! (L. B.), on seasoning wood 66, 75 

Alcohol, in corrosive sublimate 263, 265, 266, 279 

Alderson's (Captain), experiments with woods 127 

Alkali, caustic 122 

Alum, to prevent combustion 118 

„ experiments with 119 

„ and other substances 156,166,107 

American method of preserving ships' masta Ill 

„ oak, inferior to English 40 

Ammonia, to cure rot 118,137 

„ and other substances 131,286 

Amsterdam, built on piles 23 

Annual rings in wood 8 

Ants, black, how to destroy 287 

„ white, description of 240 

„ how to destroy 251,286 

„ in Australia, Bahia, and Peroambuco 245 

„ in Batavia 247 

„ in Brazil 244 

„ in Ceylon and the Philippine Islands 246 

„ in France and Japan 248 



296 INDEX. 

PACK 

Ants, white, in India 251 

„ ill Jamaica 241 

„ in Spain, Senegal, and Surinam 248 

„ woods which resist 249 

Armstrong's (J.), account of rotten floor 43 

Arsenic 224,252,287 

„ experiments with 167 

„ and other substances 253 

Asphalte, to keep out damp 179 

Australian method of seasoning Jarrah wood 115 



Baker's (J.), case of drj^ rot in Baltic wood 177 

Ballast for railway sleepers .. .... .. 48,138 

Bank of England, dry rot in dome 42 

Banks (Sir J.), on growth of fungi 44 

Barium sulphide, to preserve wood 156 

Barlow's patent process 102 

„ on seasoning wood 78 

Barnacles on timber piles 223, 226 

Barry (Sir C), on steaming wood 90 

Baryta, and other substances 166 

Basement stories with damp 23,181,182,187 

Bay onne, girder in church at 174 

Beams, advantage of sawing 32 

Bees, carpenter, destroy wood 240,259 

„ wax, and other substances 156 

Beetles, in wood 262,275 

„ how to destroy 286 

Belgian engineers prefer charred sleepers 96 

Belidor, on felling trees 54 

Bel ton House (Earl Brownlow's), beetles in carvings at .. .. 268, 281 

Bentham (Sir S.), on drying oak 91 

Benzine, to destroy wood beetles 266,277,286 

Berkeley, on fungi 21 

Bethell's (J.), patent creosoting process 130, 155, 224, 234, 286 

„ „ drying stoves 86 

Binmer, on steaming and charring 99 

Biot, on pressure process 144 

Blenheim, state of carvings at 281 

„ carvings in yellow deal at 273 

Blood, and other substances 167 

Bond timber, decay of in walls 45,174 

Borax, a receipt for black ants 287 

„ and other substances 156 



INDEX. 



297 



PACK 

Bouclierie's (Dr.), sulphate of copper process 146 

Bourne's (J.)j experiments with woods 254 

Bowring's (Sir J.), account of ants in Obamlo 247 

Boyden's (A.), remedies for dry rot 95,112,122 

Brande (Dr.), on preserving woods l^^i^, 142, 155 

Breant's patents 145 

Brick dust, tar, &c., to preserve piles 228 

Brimstone, beeswax, &c., to preserve wood 156 

Brochard and Watteau's process ^0 

Browne's (Sir S.), experiments with piles 229 

Brunei (Sir M. I.) 138,139,215,228 

Buffon 144, 198 

Builders, bad 182,202 

Building, hints on 180 

Burnett's (Sir F.), patent zinc process 140,224,254,255,286 

Burt's experience of creosoted sleepers 137 



Cadet DE Gassicourt's process for dry rot 144 

Calomel, composition of 2G4 

Calvert's caoutchouc process 162 

Camphor disliked by ants 287 

Canadian white spruce deals liable to warp 65 

„ yellow wood liable to rot in damp situations .. .. 36,43 
Caoutchouc, solution of 162 

„ and other substances 163 

Carbolic acid, for wood beetles 257,276 

Carbonate of soda (Payne's process) 154 

Carbonization by gas 97,164 

Carpenter bees destroy wood 240,259 

Carpenter (Dr.), on growth of fungi 43 

Carvers, wood 280 

Carvings destroyed by worms 266 

„ how to clean 270 

„ to destroy worms in 286 

Cashiobury, carvings at, destroyed by beetles 269 

Cement, to protect piles 227,228 

Ceylon, ants in 246 

Chalk, and other substances 161 

Ciiampys tallow process 144 

Chapman (W.), on dry rot 25, 73, 112, 119, 122, 165, 167 

Charcoal — sec' Oils, Whale, and Fish — to preserve wood 121 

„ and other substances 157 

Charpentier's hot air patent 80 

Charring wood 95 



298 iNCEx. 

PAGE 

Charring wood, when useful 100 

„ and pitching 96 

Chassloup Lambafs suggestion to prevent rot 163 

Chateau of the Eoques d'Oudres, girders at 174 

Chatsworth, Gibbons' carvings at 281 

Chelura terebrans destroy piles 219 

Chemists prefer thin creosote 131 

Chinese method of preserving wood 167 

Chippendale's carvings 281 

Chloride of calcium 146 

„ of manganese 154 

„ of sodium 164 

„ of zinc — see Burnett's Process 

Chlorine gas, and other substances 123 

Chloroform, for wood beetles 277 

Chunam, and cocoa-nut oil 107 

Church at Bay onne, fir girders in 174 

„ of Holy Trinity, Cork, rot in vaults 39 

„ in London, rot in roof 184 

„ in Surrey, „ 289 

„ of St. Mark, Venice, rot in curb 176 

„ of Old St. Pancras, London, rot in vaults 40 

Cleghorn (Dr.), on creosoted sleepers 47,136,142 

Coal Exchange, flooring of 81 

„ tar 170,233,246,256,262 

„ „ and other substances 123,284,285 

,, vessels last long 117 

Cobley's patent lime process 166 

Colocynth and quassia 263 

„ and other substances 285 

Colouring woods . . .. 108 

Commission, report of, on carvings 266,274 

Cooke's (M. C.) instance of fungi 43 

Copal varnish 191,197 

„ in linseed oil 285 

Copper, red oxide of 161 

„ prussiate of 146 

„ sulphate of — see Sulphate of Copper 

„ nitrate of 226 

„ sheathing against sea- worms 228 

„ „ and tarred felt 285 

Copperas, and coal tar 284 

„ to preserve ships 112,226 

Cork, for ends of brestsummers 174 

Corrosive sublimate 123,226,264,265,285,286 



INDEX. 299 

PAGE 

Corrosive sublimate and other substances 130, 155, 263, 2G5, 2GG, 279, 285 

Covent Garden Theatre, dry rot in bond 175 

Ck)w-dung mortar, and oils 251 

Creosote (Bethell's patent), 118, 130, 133, 142, 165, 230, 236, 255, 257, 285, 287 

„ vapour 145 

„ and chloride of zinc 133 

Crepin (M.), on creosoted wood 130,236 

Cryptogamia, or fungi 15 

Cullen's process for dry rot 157 



Dammer oil, and other substances 255 

Damp 176,177,178,181 

„ a cause of decay in wood 22 

„ rooms, how to ascertain 24 

Darwin's process for dry rot 156 

Da viller (A. C), on felling trees 54 

Davison and Symington's process 81 

Davy (Sir H.), on corrosive sublimate 127,263 

Deals require long seasoning 64 

„ how sometimes imported 35 

Deane's (Sir T.), account of dry rot case 39 

Decay of trees, symptoms of 33 

De Lapparent's processes 73,97,163 

Desiccating processes 81 

Dickson (Dr.), on Kyan's process 130 

,, (J.)j on seasoning wood 75 

Ditton Park, carvings destroyed at 269 

Donaldson's (Prof. T. L.) account of dry rot case 42 

Dondeine's paint 165 

Dorsett and Blythe's copper process 151 

Doswell's report on timber piles 232 

Dram battens liable to rot 38 

Dry rot, wet rot, and rot. 

„ appearances of 31,35 

„ causes of 24 

„ danger of 34 

„ how different from wet rot 14 

„ proceeds according to temperature 29,187 

„ caused by bad building 1 82 

„ „ mortar 44, 173, 177 

„ „ damp brickwork 44,182 

„ n „ ground 20,21 

„ „ „ stone 44 

„ „ heat and moisture 23 



300 



INDEX. 



PAGE 

Dry rot caused by insufficient areas 178 

„ ,, „ tarpaulings 184 

„ „ joining different woods 176 

„ „ kamptulicon 187 

„ „ Keene's cement 188 

„ „ oiled cloth ] 85 

„ „ old trees 183 

„ „ partial leaks 23 

„ „ want of air 171,172,186,187,188 

„ „ „ proper drains and spouts 41 

„ increased by stoves 172 

„ in ground^ under house at Hampstead 20 

„ under foundations, Norfolk House 176 

„ „ „ Grosvenor Place 176 

„ „ y?oor, Stanmore Cottage 183 

„ „ hearthstone 43 

„ „ pavement at Basingstoke 43 

„ on paved floor, Westminster Hall 44 

„ in vaults, Old St. Pancras Church 40 

„ on vaults, Holy Trinity Church, Cork 39 

„ in cask in cellar .. 43 

„ „ basement floor of house, Greenwich Frontispiece 

„ „ ground floor oihou&e^ 43,177,185,186,187 

„ „ /rs^ ^oor of house. No. 29, Mincing Lane 187 

„ „ s^conc? y?oor of house. No. 79, Gracechurch Street .. .. 187 

„ „ ham floor 42 

„ on floor of house, No. 106, Fenchurch Street, London .. .. 186 

„ m t^ooc? 6o7i(/, Covent Garden theatre 175 

„ „ damp c^os^^, or pantry 16 

„ „ wood lining to walls — basement 

„ „ floor of house in the Temple, London 124 

„ „ brestsummer of shop 42 

„ „ ^i>c?^r of house (Earl of Mansfield's) 32 

„ ,, „ building at Malta 32 

„ „ partition, No. 16, Mark Lane, London 188 

„ „ roo/, church in London 184 

» ?, » 11 Surrey 289 

„ „ cwr6 o/ c?07n^, St. Mark's, Venice 176 

„ „ dome, Bank of England 42 

„ „ „ Halle-au-Ble, Paris 42 

„ „ „ Pantheon, Paris 42 

„ „ Society of Arts building, Adelphi 42 

„ „ field gates 183 

„ „ foreign timber 35 

„ „ paling , 125 



INDEX. 301 

PAGE 

Dry Tot in ships 23,26,73,93,112,114,172 

„ prevented by seasoning G3 

„ good, cheap, and easy remedy required 291 

DuHamel 06,72,144 

Duke of Devonshire's house, dry rot at 40 

D'Uslaw's, Meyer, steam process 102 

Dutch method of coating piles 221 



Earl Brownlow's house, beetles in carvings at 268 

„ of Mansfield's house, rotten yellow fir girder at 32 

Emerson's boiled oil process for rot 110 

Endogenous stems, grow from within 4 

Engineers, English 139,288 

„ foreign, rules for sulphate of copper 151 

„ „ „ creosote 131, 133 

Evelyn (Sir J.), on seasoning wood 53,73,75 

Exogenous stems, grow from without 4 



Faraday (Prof.), on corrosive sublimate 129,263 

Felt, tarred, and copper sheathing 285 

Fences, how to prevent them rotting 46,161 

Fenchurch Street, No. 106, dry rot on floor 186 

Feuchtwanger's (Dr.), water-glass for piles 226 

Field gates, dry rot in 183 

Fire-proof houses, cost of 143 

„ „ necessity of 291 

Flemish carvings in England 280 

Flockton's wood tar process to preserve wood 130 

Floor-cloths, injurious effects of 185 

Floors, how to protect from worms 266 

„ dry rot in .. 20, 39, 40, 42, 43, 44, 125, 176, 182, 183, 186, 187 

„ „ Frontispiece 

Fluoric acid, for the black ant 287 

Fontenay's metallic soap, to preserve wood 165 

Forestier's experiments with creosoted piles 139,236 

Foundations, how to build 179 

Eraser's (Capt. A.) paint for white ants 253 

Fungi differ according to situation 22 

„ explanation of the term 15 

„ forms and strength of 31,43 

„ production of 15,18,19,20 

„ rapid growth of 44 



302 INDEX. 

PAGE 

Gambir composition for white ants 255 

Garlic and vinegar for worms 106 

Gas, carbonization of wood by 97,164 

„ chlorine, and other substances 123 

Gibbons' (Grinling), carvings 260,280 

Glue, solution of, to preserve ships 112 

„ and other substances ., 112,122,130 

Gracechurch Street, No. 79, dry rot in second floor 187 

Graham (Prof.), on Burnett's process 140 

Grease, how to take it out of floor 191 

Greenwich, rot in floor of house at Frontispiece 

Greville's (Dr.) description of fungi 21 

Groo-groo worms in Surinam 247 

Grosvenor Place, rotten planking in houses 176 

Guibert's smoke process 93 



Hales' (Dr.) oil and creosoting processes 111,118 

Halle-au-Ble, Paris, dry rot in dome of 42 

Haller's (Dr.) analysis of a fungus 31 

Hampstead, dry rot in ground of house at 20 

Hancock's caoutchouc and oil process 162 

Hartley's experiments with fire-proof house 120 

Hawkshaw's opinion of Payne's process 155 

Higgins' (Dr.) ammonia remedy for rot 118 

House, fire-proof , 120 

„ „ cost of 143 

„ badly erected 182,202 

Howe's experiments with posts 45 

Humboldt, Baron, on damp rooms 24 



Ii^ DESTRUCTIBLE Paint Company 195 

Indian Woods 47,134,223,250 

Ingredients for preserving wood 168 

Iron, cast, efl'ect of sea-water on , 230 

„ muriate of .. ., ,. .. .. 157 

„ prussiate of 146 

„ pyrolignite of 130,146,151,156,234 

„ sulphate of 154,157,284 



Jackson's preserving processes Ill 

„ (G.) experiments with white ants 254 

Jagherry, or coarse Indian sugar, for mortar 253 



INDEX. 303 

PACK 

Japanese method of treating graining 194 

Jarrah wood, how seasoned 115 

Johnson's (B.) account of rot in floor 42 

Jones* (Major, R. E.) report on rotten beams 32 

Kamptulicon causes dry rot in floors 187 

Kenwood, rotten fir girder at 32 

Kidlington, carvings in yellow deal at 273 

Klrthington Park, Gibbons* carvings at 281 

Knabb's sulphate of copper process 152 

Koenig's opinion of sulphate of copper 152 

Kyan's corrosive sublimate patent 123,205,223,233 

Lampblack, and fish oil 108 

Langton*s extraction of sap process 101 

Lead 173,179,200 

„ and tarred rope for piles 228 

„ oxide of, and other substances 123 

Lege and Fleury-Pironnet's copper patent 149 

Le Gras* manganese, zinc, and creosote patent 164 

Lepisma worm destroys boats 221 

Letellier's preserving processes 130,165 

Lewis' lime process 112,116 

Liebig (Baron) on decay of wood 19 

Lime, to preserve wood 112, 116, 253, 286 

„ and other substances 107, 117, 156, 157, 166, 255, 285 

„ recarbonated, injurious to wood 116 

„ water, to preserve ships 116,122 

„ „ „ basement joists 116 

„ „ and sulphuric acid 156 

,, vessels last long 116 

Limnoria terebrans, description of 217 

„ „ how it destroys piles 218 

Linseed oil — see Oils 
Litharge „ „ 

Logs, state of, on arrival in England 37 

Lowestoft Harbour, creosoted piles in 230 

Lukins* stove process 121 

Lycoris fucat a, destroys the Teredo navalis 237 

Lyme Hall, carvings at 281 



Maconoohie's suggestions for preserving wood 121,145,163 

McMaster (B.), on decay of railway sleepers 47 



304 INDEX. 

PAGE 

Mc William, on fungi 20,22,29 

Makinson, on creosoted piles 231 

Malta, rotten girders in building at 32 

Manganese, and other substances 163,165 

Mann's (Capt.) and MePberson's (Capt.) experiments 255 

Margary's patent sulphate of copper process 130,150,254 

Mark Lane, No. 16, dry rot in partition at 188 

Marshall (G.), on seasoning oak 69 

Maun (G. O.), on sleepers, Pernambuco railway 138 

Mecquenem's desiccating process 80 

Mollis (J. C), on creosoted wood 256 

Melseun's experiments with ammonia 137 

Mercer's Hall, decay of carvings at 267 

Mercurj^, deuto-chloride of 165 

,, bi-chloride — see Corrosive Sublimate 

Meridius lachrymans, dry rot fungus 21 

Methods for seasoning wood 168 

Methylated spirits of wine for carvings 279 

Michigan Central Railroad bridge, dry rotten • .. .. 185 

Migneron's process 144 

Miller's hot air process 102 

Mincing Lane, No. 29, dry rot in first floor at 187 

Moll's vapour of creosote process 145 

Moon, age of, a guide for cutting trees ^^ 

Mortar made with sea sand objectionable 113,181 

„ cow-dung and castor oil 251 

Mud and other substances to preserve wood 253 

Miienzing's manganese process 154 

Mundic, to preserve wood 118 

Muriate of iron (Toplis' process) .. .. 157 



Nails, scupper, for piles 228, 286 

Neamann, on seasoning wood 79,117 

Nichols (T.), on sand bath 116 

Nitrate of copper for piles 226 

Nit) ic acid, for worms 285 

Norfolk House, rotten planking at 176 

Norway white lowland deals warp 65 

Nystrom's process, to prevent combustion 166 



Oak, American, liable to rot 40 

„ diflferent qualities of 71 

„ good and bad 25 



INDEX. 305 



PAGE 



Oak seasoning 69,70,90,91 

„ panelling, if not seasoned, shrinks 288 

„ how to prevent splitting jq^j 

Ohio fireproof paint jgr 

Oil, Arracan, to protect wood from ants .>52 

„ boiled, to preserve planks of ships m 

,, castor, with cow-dung mortar 251 

„ cajeput, to protect wood from ants 247 28f ) 

„ of cedar, to protect wood from worms 10(5 

„ cocoa-nut, to preserve wood IQy 

)) V and other substances jOy 

„ dammer, and other substances 955 

»' ^sh ;* i^^ 

„ „ experiments with IQg 

M M and other substances 1q<^ 

,, Imseed '' jq^ 

„ „ and other substances 106,165,208,284,285 

'' ^li^^ '1O6 

„ of juniper, to prevent worms 285 

„ of mustard, to preserve wood lOy 

„ of spikenard 106,285 

,, of tar, and other substances 123 155 162 

„ of tar — see Coal Tar 

„ palm, to preserve wood lO^j lyy 

„ „ and other substances I23 

„ paraffin, to cure dry rot 285 

„ petroleum, to preserve wood 109,157 169 262 287 

„ „ and sand Iqq 

„ vegetable, best to preserve wood 10^^ 

„ whale 286 

„ „ renders wood brittle Iq^^ 

„ „ and other substances lOg 197 

„ and other substances 15(j -^^^ 

Oils, animal, render wood brittle ' IO7 

Oxford's patent I23 



Painting, house, described igc) 

causes rot 183,185,269 

„ how to remove from carvings 270 

Paling, rot in ]] j^- 

Pallas' iron and lime process _ Hy 

Panthe'on, Paris, dry rot in dome ^2 

Parkes' caoutchouc process I (j2 

Parry's (Dr.) suggestion to prevent rot 15g 

X 



306 INDEX. 

PAGE 

Passez's caoutchouc in sulphur process 162 

Pasteur, researches of 17 

Patents, most successful patents 169 

Payne's patent process 144,154,156,223,254 

Peat moss, for seasoning wood 116 

Penrose's report on carvings, St. Paul's Cathedral 271 

Pepys, Memoirs of, account of rot in ships in 24 

Pering on dry rot 25 

Petersburgh deals, white and yellow 38,66 

Petroleum oil to prevent rot 109,157,169,262,287 

Phillips (R.)? ^^ seasoning oak 70 

Piles, timber 23,96,219,221,223,226,228,285 

,, „ cased in iron 229 

Pine, yellow, liable to rot 43 

Pitch 96,174,224 

„ and other substances 107,159 

Pith of tree, formation of 4 

Pliny, on salt-water seasoning 72 

Polyporus by bridus fungi 21 

Porcher (Dr.), on seasoning wood 75 

Posts, experiments with 45 

„ in Norway, how preserved 173 

„ burning ends to preserve 96, 98 

,, where they decay 24 

„ coating, to preserve 161 

Potash, and other substances 166,167 

Price and Manby's drying stove 88 

Pringle (Sir J.), on the strength of alum 119 

Pritchard^s report on sea- worms 156,233 

Processes, rules for successful 110 

„ pressure and vacuum 168 

Prussiate of copper (Boucherie's process) 146 

„ of iron „ „ 146 

Pyroligneous acid 111,144,263 

Pyrolignite of iron 130,146,151,234 

and oil of tar 156 



Quassia 266,285 

„ and colocynth 263 

Quatrefages' experiments 225,242 

Quicklime, if dry, preserves wood 116 



INDEX. 307 



PAGE 



Railway sleepers, 47, 49, 74, 101, 103. 125, 134, 13G, 138, 140, 143, 

149, 151, 152, 251, 254 

Ranee's experiments with chloride of sodium 164 

Randall (J.), on oxidating wood 98 

Ransome's silicate of soda process 156 227 

Rats, how to get rid of I73 

Raid's vegetable acid process .. .. HI 

Remedies for white ants 286 

,, for black ants 287 

„ fordryrot 284 

,, worms in carvings 286 

„ ^ „ in piles 285 

Renwick's vapour of creosote process 146 

Resin, and other substances 122 159,161,285 

Robins, oleaginous vapour process I57 

Rogers (W. J.), the wood carver 72 2G8 274 

Rot, internal causes of 32 

„ in timber, how to ascertain 33,185 

>» »} to prevent 283 

jy i, to cure 284 



Salt, bay, to preserve ships 114 

„ common, to preserve ships 112 

» V to preserve railway sleepers 74 

„ water, lime, &c., to preserve wood 73,111 

„ vessels last long II4 

Saltpetre, to preserve ships II4 

Salts, deliquescent, corrode metals 112 

Sand and coal tar 284 

„ and petroleum 109 

?j bath 21(5 

»' sea 113,181 

Sapwood in different woods 3 

Saturating woods to resist beetles 279 

Scott's (Col.) paint for ants 253 

Sea salt and copperas Ig^ 

»' s^^d 113,181 

„ water, effect of, on iron 230 

yi weed 213 

„ worms 203 

Seasoning by air, and exposure in stacks 64 

,» „ heated gQ 

„ by extraction of sap 101 

„ „ water, fresh 7I 

X "2 " 



308 INDEX. 

PAGE 

Seasoning by water, salt 73, 1] 3 

„ „ ,, „ sea-weed, and sea-sand 115 

„ „ „ lime 73, 111 

,, „ smoke 91 

„ „ steaming and boiling 77 

„ „ charring 99 

„ gas 97,164 

„ „ sand bath 116 

„ „ scorching and charring 95,97 

„ „ baking 79,81,86,88,94 

„ oak .. 69,70,72,289 

., second 103 

Sea-worms, woods which resist 223 

Selenite, experiments with 119 

Shakesinwood 10,249,250 

Shaw (Capt. E. M.), on admission of air .. 120,171 

Shield's remedy for white ants 245, 256 

Ships 99,111,112,114,116,117,194,251 

„ dry rot in .. ..23,26,73,93,112,114 

Silicate of potash 155 

„ of soda 156,160,227 

„ „ and lime 160 

Silloway (T. W.), on seasoning wood 75, 92 

Silver grain .... 6 

Size for wood, why required 197 

„ and corrosive sublimate 266 

Slating wall to keep out damp 177 

Sleepers, see Eailway Sleepers 

Smirke (Sir K.)» on dry ix)t 20,123 

Smith's solution for wood beetles 264 

Soap, experiments with 122 

„ metallic, to preserve wood 165 

„ yellow „ „ 165 

,, and other substances 253 

Society of Arts building, dry rot in 42 

Soda, carbonate of 155 

Soluble glass 155 

Southend pier, attacked by sea-worms 209 

Spores, description of ] 5 

Stains for woods 189,197 

Stanmore Cottage, dry rot in floor at 183 

Steam 145,168 

„ — sec Seasoning by Steam 

Stephenson (Sir M.), on crcosoted wood 134 

Stevenson (R.), on timber piles 205,217 



INDEX. 309 

PAGE 

St. James's Church, Piccadilly, carvings at 272,281 

St. Helena, experiments with woods at 256 

St. Mark's, Venice, rotten curb of dome at 176 

St. Paul's Cathedral, London 42,271,290 

St. Preuve's steam process 80 

Stove dryino^ 79,81,86,88,94 

Strength of timber 11 

Strontia, and other substances 166 

Sublimate — see Corrosive Sublimate 

Sulphate of copper 122, 146, 149, 150, 151, 161, 226, 284 

„ ,, and sulpliuric acid 285 

„ of iron 154,157,284 

„ „ and other substances 117,160,284 

Sulphur 163 

„ in other substances 163,285 

Sulphuric acid 101,285 

Surinam, groo-groo worms in 247 

Swift's, Dean, recipe for beetles 282 

Tallow bath for wood 144 

Tar, and other substances 106,130,159,228,251,284 

Tarred rope, and lead for piles 228 

Teak oil, to preserve wood from ants 259 

,, chips, distilled 163 

Temple of Diana, at Ephesus, built on charred piles 98 

„ buildings, London, dry rot in 124 

Tennant's (Sir E.) account of ants in Ceylon 246 

„ „ bees „ 260 

Teredo navalis, description of 212 

,, — see Worms, Sea 
Termites — see Ants, White 

Tie-beam, instance of unseasoned 289 

Timber depreciates by keeping too long 64 

Tissier's hot air process 102 

Toplis' sulphate of iron process 157 

Tredgold (T.), on seasoning wood 78,101,290 

Treenails 26,110,118 

Trees, symptoms of decay in 52 

„ how to prepare for felling 61 

„ when to fell 53, 54, 55, 58 

Trinity College, Cambridge, carvings at 209,273 

„ Oxford „ 269,273 

Truman's brewery, seasoning casks at 84 

Turpentine prevents rot 36,257,263,285 

„ in corrosive sublimate 115 



310 INDEX. 

PAGE 

Uninflammable wood, good process required for 170,291 

Unseasoned oak panelling 288 

„ roof principal 289 



Vaporizing woods 276 

Vapour of creosote process 145 

Venice, built on piles 23 

Vernet's fireproof method 167 

Vessels in coal trade last long ;. .. 117 

„ in lime „ 116 

„ in salt „ 114 

Vinegar — see Garlic 
Vitriol, blue — see Sulphate of Copper 
„ green — see Sulphate of Iron 

Vitruvius on seasoning wood .. 75 

Vulliamy (G.), on charring posts 96 



Wade's suggestions for preserving wood 119,122 

Wainscot, Crown Kiga 90 

dry rot in 35,125 

„ how to cut oak for 70 

„ unseasoned oak for 289 

Wallis' experiments with beetles 276 

Walnut juice for worms 263 

Warburton's (H.) opinion of American oak 40 

Warping of boards 66, 67 

Water in wood 39,67,180 

„ in church 29 

„ glass to preserve piles 226 

Watson's (Dr.) experiments with wood 67 

Westwood's (Prof.) report on wood beetles 262 

Wet rot, how caused 14,28 

Wimpole, carvings at 273 

Wood bond decays "175,176 

„ progress of decay in 19 

„ (Rev. J.), on worms and ants 211,265 

Woods best when not painted 189 

„ experiments with 46,58,67 

„ french polished 192 

„ white, improved by water seasoning 72 

„ which resist beetles 273 

sea-worms 223 



?? j> 



INDEX. 311 

PAGE 

Woods which resist white ants 249 

Woodcutters .. 55 

„ tricks of Indian 11 

„ tricks, of, in Ceylon 114 

Woody fibre, formation of 2,7 

Worms, sea 203 

„ how to prevent in wood 285 

Wren(SirC.) 23,98,221,271 



Zinc, chloride of — see Burnett's Process 

„ sulphate of 122 

„ white oxide of 226 

„ and other substances 165 



PRINTED BT WILLIAM CLOWES AKD SONS, STAMFORD STREET AND CHAEINO CBOSS. 



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Welch, Mem. Inst. Mech. Engineers, Author of ' Designing Valve 
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A Handbook of Formnlc^, Tables, and Memoranda, 

for Architectural Surveyors and others engaged in Building, By J. T. 
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Containing : 

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Practical Directions for the Treatment, Care, and Management of Belts. 
Descriptions of many varieties of Beltings, together with chapters on the 
Transmission of Power by Ropes ; by Iron and Wood Frictional Gearing ; 
on the Strength of Belting Leather ; and on the Experimental Investiga- 
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Spons Bttilders Pocket-Book of Prices and Memo- 
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ready, 

Long-Span Raihvay Bridges, comprising Investiga- 
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various adopted or proposed Type Systems of Construction, with numerous 
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Investigations and Tables relating to Short-span Railway Bridges. Second 
and revised edition. ByB. Baker, Assoc. Inst. C.E. Plates, crown 8vo, 
cloth, 5J-. 

Elementary Theory and Calculation of Iron Bridges 

and Roofs. By August Ritter, Ph.D., Professor at the Polytechnic 
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The Btiilders Clerk : a Guide to the Management 

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The Elementary Principles of Carpentry, By 

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Section I. On the Equality and Distribution of Forces — Section II. Resi^^tance of 
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tion V. Construction of Domes and Cupolas— Section VI. Construction of Partitions — 
Section VII. Scaffolds, Staging, and Gantries — Section VIII. Construction of Centres for 
Bridges— Section IX. Coffer-dams, Shoring, and Strutting— Section X. Wooden Bridges 
and Viaducts— Section XI. Joints, Straps, and other Fastenings— Section XII. Timber. 

Engineering Notes, By Frank Robertson, Fellow 

Roy. Astron. Soc, late first Lieut. R.E., and Civil Engineer Public 
Works Department in India. 8vo, cloth, \2s. 6d. 

The object of this work is to supply an exhaustive digest of all that is known on each 
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B 2 



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The Electric Light in its Practical Application, By 

Paget Higgs, LL.D., D.Sc, Telford Prizeman, and Associate Member 
of the Institution of Civil Engineers. With 94 illustrations, 240 pages. 
Demy 8vo, cloth, 9.. Contents : 

Introductory — Lamps or Burners Employing the Voltaic Arc — Electric ''Candles" and 
Candle Lamps — Lighting by Incandescence — Magneto and Dynamo-electric Machines — 
Mechanical Efficiency of Electric Light Machines — Simple Mathematical Considerations 
Concerning Electric Lighting — Electric Regulators — Commercial Aspect of Electric Lighting 
— Division of the Electric Light — Maritime and Military Aspects — Various Applications of 
the Electric Light — Electric Carbons. 

Progressive Lessons in Applied Science. By Edward 

Sang, F.R.S.E. Crown 8vo, cloth, each Part, 3^. 

Part I. Geometry on Paper — Part 2. Solidity, Weight, and Pressure— Part 3. Trigono- 
metry, Vision, and Surveying Instruments. 

A Practical Treatise on Casting and Founding, 

including descriptions of the modern machinery employed in the art. By 
N. E wSpretson, Engineer. With 82 plates drawn to scale, 412 pp. 
Demy 8vo, cloth, iSj. 

A Practical Treatise on Coal Mining. By George 

G. Andre, F.G.S., Assoc. Inst. C.E., Member of the Society of Engineers. 
With 82 lithographic plates, 2 vols., royal 4to, cloth, 3/. 12s, 

Contents : 

I. Practical Geology — II. Coal, its Mode of Occurrence, Composition, and Varieties — III. 
Searching for Coal — IV. Shaft-sinking — V. Driving of Levels, or Narrow Work — VL Systems 
of Workmg— Vll. Getting the Coal— VIII. Haulage— IX. Windinc:— X. Drainage— XL 
Ventilation — XIL Incidental Operations — XIII. Surface Work — XIV. Management and 
Accounts — XV. Characteristics of the Coal Fields of Great Britain and America. 

The Electric Transmission of Power,, its Present 

Position and Advantages. By PAGET HiGGS, LL.D., D.Sc. Telford 
Prizeman, and Associate Member of the Institution of Civil Engineers. 
With numerous illustrations. Crown 8vo, cloth, 3^. 

Contents : 

Dynamo-electric Machines — The Gramme Machine — The Brush Machine — The Wallace- 
Farmer and Siemens Machines — Efficiency of Dynamo-electric Machines — Practicability of 
the Transmission of Power by Electricity — Efficiency of Coupled Machines— Comparative 
Efficiency of Various Machines — Other Theoretical Considerations— Conclusions. 

The Clerk of Works: a Vade-Mecum for all engaged 

in the Superintendence of Building Operations. By G. G. HosKiNS, 
F.R.I.B.A. Fcap. 8vo, cloth, \s, 6d. 

Coffee Planting in Southern Lndia a7id Ceylon. By 

E. C. p. Hull. Crown 8vo, cloth, 9^. 



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Spoils' l7ifo7'matio7i for Colonial Engmcers. Edited 

by J. T. Hurst. Demy 8vo, sewed. 

No. I, Ceylon. By Abraham Deane, C.E. 2i-. ed. 

Contents : 

Introductory Remarks— Natural Productions — Architecture and Engineering — Topo- 
graphy, Trade, and Natural History— Principal Stations— Weights and Measures, ?tc., etc. 

No. 2. Southern Africa, including the Cape Colony, Natal, and the 
Dutch Republics. By Henry Hall, F.R.G.S., F.R.C.I. With 
Map. -is. 6d, ^ 

Contents : 

General Description of South Africa— Physical Geography with reference to Engineering 
Operations— Notes on Labour and Material in Cape Colony— Geological Notes on Rock 
Formation in South Africa— Engineering Instruments for Use in South Africa— Principal 
Public Works in Cape Colony: Railways, Mountain Roads and Passes, Harbour Works 
Bridges, Gas Works, Irrigation and Water Supply, Lighthouses, Drainage and Sanitary 
Engineering, Public Buildings, Mines— Table of W^oods in South Africa— Animals used for 
Draught Purposes— Statistical Notes— Table of Distances— Rates of Carriage, etc. 

No. 3. India. By F. C. Danvers, Assoc. Inst. C.E. With Map. 4?. 6d. 

Contents : 

_ • Physical Geography of India— Building Materials— Roads— Railways-Bridges— Irriga- 
tion- River Works — Harbours — Lighthouse Buildings — Native Labour — The Principal 
1 rees of India— Money— Weights and iMeasures— Glossary of Indian Terms, etc. 

Tropical Agrictdhtre ; or, the Culture, Preparation, 

Commerce, and Consumption of the Principal Products of the Vegetable 
Kingdom, as furnishing Food, Clothing, Medicine, etc., and in their 
relation to the Arts and Manufactures ; forming a practical treatise and 
Handbook of Reference for the Colonist, Manufacturer, Merchant, and 
Consumer, on the Cultivation, Preparation for Shipment, and Commercial 
Value, etc., of the various Substances obtained from Trees and Plants 
entering into the Husbandry of Tropical and Sub-Tropix:al Regions. By 
P. L. SiMMONDS. Second edition, revised and improved, 515 padres, 
8vo, cloth, i/. I J. *^ 



Steely its History^ Manufacture, and Uses. By 

J. S. Jeans, Secretary of the Iron and Steel Institute. 860 pages and 
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— II. Russia — 12. Sweden — 13. Other Countries. Section II., Manufacture of Steel: 
Chap. 14. Cementation and other Methods — 15. Manufacture by Bessemer Process — 16. 
Siemens-Martin Process— 17. Other Methods. Section III., Chemical and Physical 
Properties of Steel: Chap. 18. Phosphorus in Steel— 19. The Use of Manganese— 20. 
Spiegeleisen — 21. Sulphur in Steel — 22. Silicon in Steel — 23. Tensile Strength of Steel — 24. 
Mechanical Tests of Steel — 25. Analysis of Steel. Section IV., Uses of Steel: Chap. 26. 
Application, of Steel to Railway Purposes— 27. To Shipbuilding— 28. To Bridge Building— 
29. To General Purposes — 30. Guns and Armour Plates — 31. Other Purposes. 



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Compensations: a Text-book for Surveyors, in Tabu- 
lated Form, liy BANISTER Fletcher. Crown %mo, cloth, 5^-. 

Contents : 

The Varieties of Damage for which Claims may arise — Various Classes of Property — 
Points to be observed in Surveys — Notices to Treat — Nature of Damage for which Claims 
can and cannot be sustained — What Property can be compulsorily taken — When Entry on 
Property can and cannot be compulsorily made — Of Goodwill and Stock — and of the various 
Legal Methods of Settlement of Disputed Claims — together with Full and Explicit Instruc- 
tions on the Methods of Valuing and of Making Claims ; with Comments on Cases arising 
under the Metropolis Local Management and MetropoHtan Buildings Acts ; the whole given 
in a Practical and Comprehensive Form, supplemented by a copious Appendix, containing 
many Useful Forms and Precedents, and also Tables for the Valuation of Freeholds, Lease- 
holds, Reversions, and Life-Interests. 

Dilapidations: a Text-book for Architects and Sur- 
veyors, in Tabulated Form. By Banister Fletcher, Fellow Royal 
Inst. Brit. Arch. (Author of * Model Houses '). Showing who are liable for 
Dilapidations, and the extent of the liability of Lessors, Lessees, Tenants 
at will, Tenants by elegit, Statute, Merchant, or Staple Tenants in fee 
simple, Tenants in .tail, Tenants for life, Tenants for years without 
impeachment of Waste, Mortgagor, Mortgagee in possession, Yearly 
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surveyor how to take and value them, to which is added the duties of 
surveyors, with a table of legal cases, embracing the most recent, and 
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and latest legal decisions. Crown 8vo, cloth, 5^, 

Quantity Surveying, for the us€ of Architects, Builders, 

and Engineers. By J. LEANING. With 42 illustrations. 375 pages, 
crown 8vo. cloth, 9^-. 

Sponi^' Dictionary of Engineering, Civil, Mechanical, 

Military^ and Naval; with technical terms in French, German, Italian, 
and Spanish, 3100 pp., and nearly 8000 engravings, in super-royal 8vo, 
in 8 divisions, 5/. 8^-. Complete in 3 vols., cloth, 5/. 5J". Bound in a 
superior manner, half-morocco, top edge gilt, 3 vols., 6/. 12.S. 

See page 16. 

A Treatise on the Origiji, Progress, Prevention, and 

Cure of Dry Rot in Tifnber; with Remarks on the Means of Preserving 
Wood from Destruction by Sea- Worms, Beetles, Ants, etc. By Thomas 
Allen Britton, late Surveyor to the Metropolitan Board of Works, 
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Metrical Tables, By G. L. Molesworth, M.I.C.E. 

32mo, cloth, \s. 6d. 

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General — Linear Measures — Square Measures — Cubic Measures — ^Measures of Capacity. — 
Weights — Combinations — Thermometers. 



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A Handbook of Electrical Testing. By H. R. 

Kempe, Assoc, of the Society of Telegraph Engineers. With Illustra- 
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Electricity ; its Theory, Sources, and Applications. 

By John T. Sprague, Member of the Society of Telegraph Engineers. 
With 91 woodcuts and 30 valuable Tables. Crown 8vo^ cloth, Zs. 



Electro -Telegraphy, By Frederick S. Beechey, 

Telegraph Engineer, a Book for Beginners. Fcap. 8vo, cloth, u. 6^. 



Handraili^ig : by the Square Ctit. By John Jones, 

Staircase Builder. Fourth edition. With srjen plates, Svo, cloth, 3^. 6^/. 



Spons Engineers and Contractors Illustrated Book 

of Prices of Machijtes, Tools , Ironwork^ and Contractors'^ Material ; 
a7td Engineers^ Directory, Third edition, 4to, cloth, 6s. 



The Gas Co7isumer s Handy Book. By William 

Richards, C.E. Illustrated. iSmo, sewed, 6d, 



A Practical Treatise on N alter al and Artificial 

Concrete^ its Varieties and Constructive Adaptations. By Henry Reid, 
Author of the * Science and Art of the Manufacture of Portland Cement.' 
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The Gas Analyst's Mamial. By F. W. Hartley, 

Assoc. Inst. C.E., etc. With numerous illustrations. Crown Svo, 
cloth, 6j. 



The French - Polisher s Manual, By a French- 

Polisher; containing Timber Staining, Washing, Matcliing, Improving, 
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Smoothing, Spirit Varnishing, French-Polishing, Directions for Re- 
polishing. Third edition, royal 32mo, sewed, 6d. 



8 CATALOGUE OF SCIENTIFIC BOOKS 



A Pocket-Book of Useful FonmilcE and Me7noranda 

for Civil and Mechanical E^igiiieers. By GuiLFORD L. Molesworth, 
Mem. Inst. C. E., Consulting Engineer to the Government of India for 
State Railways. Twentieth edition, 32mo, roan, ds. ; or printed on India 
paper and bound in pocket-book form, in russia or morocco, *]s. 6d, 

Synopsis of Contents: 

Surveying, Levelling, etc. — Strength and Weight of Materials — Earthwork, Brickwork, 
Masonry, Arches, etc. — Struts, Columns, Beams, and Trusses — Flooring, Roofing, and Roof 
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Waterworks, Docks — Irrigation and Breakwaters — Gas, Ventilation, and Warming — Heat, 
Light, Colour, and Sound — Gravity : Centres, Forces, and Powers — Millwork, Teeth of 
Wheels, Shafting, etc. — Workshop Recipes — Sundry Machinery — Animal Power — Steam and 
the Steam Engine — Water-power, Water-wheels, Turbines, etc. — Wind and Windmills — 
Steam Navigation, Ship Building, Tonnage, etc. — Gunner^'-, Projectiles, etc. — Weights, 
Measures, and Money — Trigonometry, Conic Sections, and Curves — Telegraphy — Mensura- 
tion — Tables of Areas and Circumference, and Arcs of Circles — Logarithms, Square and 
Cube Roots, Po^vers — Reciprocals, etc. — Useful Numbers — Differential and Integral Calcu- 
lus — Algebraic Signs — Telegraphic Construction and Formulae. 

"Most of our readers are already acquainted with Molesworth's Pocket-book, and not a 
few, we imagine, are indebted to it for valuable information, or for refreshers of the memory. 
The book has been re-arranged, the supplemental formulae and tables added since the first 
issue having now been incorporated with the body of the book in their proper positions, the 
whole making a handy size for the pocket. Every care has been taken to ensure correctness, 
both clerically and typographically, and the book is an indispensable vade-meciun for the 
mechanic and the professional man." — E^iglish Mechanic. 

Spons Tables and Memoranda for Engineers; 

selected and arranged by J. T. Hurst, C.E., Author of * Architectural 
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gilt edges, third edition, revised and improved, \s. Or in cloth case, 
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This work is printed in a pearl type, and is so small, measuring only 2^ in. by if in. by 
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*' It is certainly an extremely rare thing for a reviewer to be called upon to notice a volume 
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coat pocket, and containing a far greater amount and variety of information than most people 
would imagine could be compressed into so small a space. . , . . The little volume has been 
c'ompiled with considerable care and judgment, and we can cordially recommend it to our 
readers as a useful little pocket companion." — Engineering. 

Analysis, Technical Valuation, Purification and Use 

of Coal Gas. By the Rev. W. R. BowDlTCH, M.A. With wood ejigravings, 
8vo, cloth, I2s. 6d. 

Condensation of Gas — Purification of Gas — Light — Measuring — Place of Testing Gas — 
Te^t Candles — The Standard for Measuring Gas-light — Test Burners — Testing Gas for 
Sulphur — Testing Gas for Ammonia — Condensation by Bromine — Gravimetric Method of 
taking Specific Gravity of Gas — Carburetting or Naphthalizing Gas — Acetylene — Explosions 
of Gas — Gnawing of Gaspipes by Rats— Pressure as related to Public Lighting, etc. 

Hops, their Cultivation, Commerce, and Uses in 

various Countries, By P. L. SiMMONDS. Crown 8vo, cloth, 4J. 6</. 



PUBLISHED BY E. & F. N. SPON. 



A P^^actical Treatise on the Maiui/actttre and Distri- 
bution of Coal Gas. By William Richards. Demy 4to, with numerous 
"djood engravings a7id large plates y cloth, 2%s. 

Synopsis of Contents : 

Introduction — History' of Gas Lighting — Chemistry of Gas Manufacture, by Lewis 
Thompson, Esq., AI.R.C.S. — Coal, with Analyses, by J. Paterson, Lewis Thompson, and 
G. R. Hislop, Esqrs. — Retorts, Iron and Clay — Retort Setting — Hydraulic Main — Con- 
densers — Exhausters — Washers and Scrubbers — Purifiers — Purification — History of Gas 
Holder — Tanks, Brick and Stone, Composite, Concrete, Cast-iron, Compound Annular 
Wrought-iron — Specifications — Gas Holders — Station M eter — Governor — Distribution — 
Mains — Gas Mathematics, or Formulae for the Distribution of Gas, by Lewis Thompson, Esq. — 
Services — Consumers' Meters — Regulators — Burners — Fittings — Photometer — Carburization 
of Gas — Air Gas and Water Gas — Composition of Coal Gas, by Lewis Thompson, Esq. — 
Analyses of Gas — Influence of Atmospheric Pressure and Temperature on Gas — Residual 
Products — Appendix — Description of Retort Settings, Buildings, etc., etc. 

Pi^actical Geometry and Engineering Drawing ; a 

Course of Descriptive Geometiy adapted to the Requirements of the 
Engineering Draughtsman, including the determination of cast shadows 
and Isometric Projection, each chapter being followed by numerous 
examples ; to which are added rules for Shading Shade-lining, etc., 
together with practical instructions as to the Lining, Colouring, Printing, 
and general treatment of Engineering Drawings, with a chapter on 
drawing Instruments. By George S. Clarke, Lieut. R.E., Instructoc 
in Mechanical Drawing, Royal Indian Engineering College, Cooper's 
Hill. 20 plates, 4to, cloth, 15J". 

The Ele7nents of Graphic Statics. By Professor 

Karl Von Ott, translated from the German by G. S. Clarke, Lieut. 
R.E., Instructor in Mechanical Drawing, Royal Indian Engineering 
College, Cooj^er's Hill. Crown 8vo, cloth, ^s. 

See page 3. 

A Practical Treatise on Heat, as applied to the 

Useful Arts; for the Use of Engineers, Architects, etc. By Thomas 
Box. With la^ plates. Third edition, crown 8vo, cloth, \2s. 6d. 

The New Formnla for Mean Velocity of Discharge 

of Rivers and Canals. By W. R. Kutter, translated from articles in 
the ' Cultur-Ingenieur.' By Lowis D'A. Jackson, Assoc. Inst. C.E. 
8vo, cloth, I2J. ^d. 

Hydraulics of Great Rivers ; being Observations and 

Surveys o?t the Largest Rivers of the World. By J. J. Revy. Imp. 4to, 
cloth, with eight large plates and charts, 2/. 2s. 

Practical Hydraulics ; a Series of Rules and Tables 

for the use of Engineers, etc., etc. By Thomas Box. Fifth edition, 
mimerous plates^ post Svo, cloth, 5^. 



10 CATALOGUE OF SCIENTIFIC BOOKS 



The Indicato7^ Diagram Practically Considered, By 

N. P. Burgh, Engineer. Numerous ilhcstrations^ fifth edition. Crown 
8vo, cloth, 6j-. 6^. 

" This volume possesses one feature which renders it almost unique ; this feature is the 
mode in which it is illustrated. It is not difficult to take a diagram if the instrument is once 
set, and the setting with stationary engines is occasionally easy enough, but circumstances 
continually arise under which the young engineer is completely at a loss as to how to obtain 
a diagram. All uncertainty will be removed by referring to the book under consideration : 
here we have drawings of the arrangements to be adopted under every conceivable circum- 
stance, drawings, we may add, illustrating the practice of the best engineers of the day."*— 
Efigitieer. 

Link- Motion and Expansion Gear Practically Con- 
sidered, By N. P. Burgh, Engineer. Illustrated with ^o plates and 22^ 
wood engravings, small 4to, cloth, 30^. 

The Mechanician and Constructor for Engineers, 

comprising Forging, Planing, Lining, Slotting, Shaping, Turning, Screw 
Cutting, etc. By Cameron Knight. Containi7tg 96 plates, 1147 illus- 
trations, and y)*j pages of letterpress. Cheaper edition, cloth, iSj. 

The Essential Elements of Practical Mechanics; 

based on the Principle of Work, designed for Engineering Students. By 
Oliver Byrne, formerly Professor of Mathematics, College for Civil 
Engineers. Third edition, illustrated by mwierous wood engravings^ 
post 8vo, cloth, 7J-. dd. 

Contents : 

Chap. I. How Work is Measured by a Unit, both with and without reference to a Unit 
of Time — Chap. 2. The Work of Living Agents, the Influence of Friction, and introduces 
one of the most beautiful Laws of Motion — Chap. 3. The principles expounded. in the first and 
second chapters are applied to the Motion of Bodies — Chap. 4. The Transmission of Work by 
simple Machines — Chap. 5. Useful Propositions and Rules. 

The Practical Millwright's and Engineer s Ready 

Reckoner; or Tables for finding the diameter and power of cog-wheels, 
diameter, weight, and power of shafts, diameter and strength of bolts, etc. 
By Thomas Dixon. Fourth edition, i2mo, cloth, 3J". 

Contents: 

Diameter and Power of Wheels — Diameter, Weight, and Power of Shafts — Multipliers for 
Steam used Expansively — Diameters and Strength of Bolts — Size and Weight of Hexagonal 
Nuts — Speed of Governors for Steam Engines — Contents of Pumps — Working Barrels — Cir- 
cumferences and Areas of Circles — Weight of Boiler Plates — French and English Weights and 
Measures, etc 

The Principles of Mechanics and their Application to 

Prime Movers, Naval Architecture, Iron Bridges, Water Supply, etc. By 
W. J. Millar, C.E., Secretary to the Institution of Engineers and Ship- 
builders, Scotland. Crown 8vo, cloth, /\s, 6d, 



PUBLISHED BY E. & R N. SPON. ii 



A Practical Treatise on Mill-gearing, Wheels, Shafts, 

Rigs^ers, etc. ; for the use of Engineers. By ThOxMAS Box. Crown 8vo, 
cloth, with 1 1 plates, second edition, yj*. 6^. 

Mining Machinery: a Descriptive Treatise on the 

Machinery, Tools, and other Appliances used in Mining. By G. G. 
Andre, F.G.S., Assoc. Inst. C.E., Mem. of the Society of Engineers. 
Royal 4to, uniform with the Author's Treatise on Coal Mining, con- 
taining 182 plates, accurately drawn to scale, with descriptive text, in 
2 vols., cloth, 3/. I2s. 

Contents : 

Machinery for Prospecting, Excavating, Hauling, and Hoisting — Ventilation — Pumpinp — 
Treatment of Mineral Products, including Gold and Silver, Copper, Tin, and Lead, Iron, 
Coal, Sulphur, China Clay, Brick Earth, etc. 

The Pattern Makers Assistant ; embracing Lathe 

Work, Branch Work, Core Work, Sweep Work, and Practical Gear 
Construction, the Preparation and Use of Tools, together with a larre 
collection of Useful and Valuable Tables. By Joshua Rose, M.E. 
^Vith 250 ilhtstrations. Crown 8vo, cloth, loj. ^d. 

The Science and Art of the Mamfacture of Portland 

Ce77ient, with observations on some of its constructive applications, with 
7iicme7'ous illustrations. By Henry Reid, C.E., Author of *A Practical 
Treatise on Concrete,' etc., etc. 8vo, cloth, iZs. 

The Dranghtsman s Handbook of Plan and Map 

Drawing; including instructions for the preparation of Engineering, 
Architectural, and Mechanical Drawings. With mc?nero2is illustrations 
i7t the text^ and 33 plates (15 printed in coloicrs). By G. G. Andrk, 
F.G.S., Assoc. Inst. C.E. 4to, cloth, reduced to 91. 

Contents : 

The Drawing Oftice and its Furnishings — Geometrical Problems — Lines, Dots, and their 
Combinations — Colours, Shading, Lettering, Bordering, and North Points — Scales — Plotting 
— Civil Engineers' and Surveyors' Plans — Map Drawing — Mechanical and Architectural 
Drawing — Copying and Reducing Trigonometrical Formulae, etc., etc. 

The Railway Btcilder : a Handbook for Estimating 

the Probable Cost of American Railway Construction and Equipment. 
By William J. Nicolls, Civil Engineer. Illustrated, full bound, pocket- 
book form, 7 J. 6c/. 

Rock Blasting: a Practical Treatise on the means 

employed in Blasting Rocks for Industrial Purposes. By G. G. Andre, 
F.G.S., Assoc. Inst. C.E. With 56 illustrations and 12 plates, 8vo, cloth, 
lOj-. 6^/. 



12 CATALOGUE OF SCIENTIFIC BOOKS 



Surcharged and different Forms of Retaining Walls, 

By J. S. Tate. Cuts, 8vo, sewed, 2s, 

A Treatise on Ropemaking as practised in public and 

pi'ivate Rope-yards, with a Description of the Manufacture, Rules, Tables 
of Weights, etc., adapted to the Trade, Shipping, Mining, Railways, 
Builders, etc. By R. Chapman, formerly foreman to Messrs. Huddart 
and Co., Limehouse, and late Master Ropemaker to H.M. Dockyard, 
Deptford. Second edition, i2mo, cloth, 3^. 

Sanitary Engineering ; a Series of Lectures given 

before the School of Engineering, Chatharn, Division I. Air. — Division II. 
Water. — Division III. The Dwelling. — Division IV. The Town and 
Village. — Division V. The Disposal of Sewage. Copiously illustrated. 
By J. Bailey Denton, C.E., F.G.S., Honorary Member of the Agri- 
cultural Societies of Norway, Sweden, and Hanover, and Author of the 
* Farm Homesteads of England,' * Village Sanitary Economy,' * Storage 
of W^ater,' 'Sewage Farming,' etc. Royal 8vo, cloth, 2^s. 

Sa7iitary Engineering: a Guide to the Construction 

of Works of Sewerage and House Drainage, with Tables for facilitating 
the calculations of the Engineer. By Baldwin Latham, C.E., M. Inst. 
C.E., F.G.S., F.M S., Past-President of the Society of Engineers. Second 
edition, with numerous plates and Tvoodciits, 8vo, cloth, i/. \Qs, 

A Practical Treatise on Modern Screw-Propulsion. 

By N. P. Burgh, Engineer. Illustrated with 52 large plates and 103 
woodcuts, 4to, half-morocco, 2/. 2x. 

Screw Cutting Tables for Engineers and Machinists, 

giving the values of the different trains of Wheels required to produce 
Screws of any pitch, calculated by Lord Lindsay, M.P., F.R.S., F.R.A.S., 
etc. Royal 8vo, cloth, oblong, 2s. 

Screw Cutting Tables, for the use of Mechanical 

Engineers, showing the proper arrangement of Wheels for cutting the 
Threads of Screws of any required pitch, with a Table for making the 
Universal Gas-pipe Threads and Taps. By W. A. Martin, Engineer. 
Second edition, royal 8vo, oblong, cloth, \s. 

Treatise on Valve-Gears, with special consideration 

of the Link-Motions of Locomotive Engines. By Dr. GuSTAV Zeuner. 
Third edition, revised and enlarged, translated from the German, with the 
special permission of the author, by MORITZ MiJLLER. Plates, 8vo, 
cloth, 1 2 J. (id. 



PUBLISHED BY E. & F. N. SPON. 13 



Cleaning and Scouring : a Manual for Dyers, Laun- 
dresses, and for Domestic Use. By S. Christopher. iSmo, sewed, 6d, 

A Treatise on a Practical Method of Designing Slide- 

Valve Gears by Simple Geo?netrical Constructio7i^ based upon the principles 
enunciated in Euclid's Elements, and comprising the various forms of 
Plain Slide-Valve and Expansion Gearing ; together with Stephenson's, 
Gooch's, and Allan's Link-Motions, as applied either to reversing or to 
variable expansion combinations. By Edward J. Cowling Welch, 
Memb. Inst. Mechanical Engineers. Crown 8vo, cloth. 6j. 

The Slide Valve practically considered. By N. P. 

Burgh, Engineer. Ninth edition, luith %Z illustratiofiSy crown 8vo, 
cloth, 5^. 

A Pocket-Book for Boiler Makers and Steam Users, 

comprising a variety of useful information for Employer and Workman, 
Government Inspectors, Board of Trade Surveyors, Engineers in charge 
of Works and Slips, Foremen of Manufactories, and the general Steam- 
using Public. By Maurice John Sexton. Royal 32mo, roan, gilt 
edges, Sj-. 

Modern Compotcnd E^igines ; being a Supplement to 

Modern Marine Engineering. By N. P. Burgh, Mem. Inst. Mech. Eng. 
Numerous large plates of working draivingSy 4to, cloth, i8j". 

The following Firms have contributed Working Drawings of their best and most modern 
examples of Engines fitted in the Royal and Mercantile Navies : Messrs. Maudslay, Rennie, 
Watt, Dudgeon, Humphreys, Ravenhill, Jackson, Perkins, Napier, Elder, Laird, Day, 
Allibon. 

A Practical Treatise on the Steam Engine, con- 
taining Plans and Arrangements of Details for Fixed Steam Engines, 
with Essays on the Principles involved in Design and Construction. By 
Arthur Rigg, Engineer, Member of the Society of Engineers and of 
the Royal Institution of Great Britain. Demy 4to, copiously illustrated 
with woodcuts and 96 plates^ in one Volume, half-bound morocco, 2/. 2s. ; 
or cheaper edition, cloth, 2^s. 

This work is not, in any sense, an elementary treatise, or history of the steam engine, but 
is intended to describe examples of Fixed Steam Engines without entering into the wide 
domain of locomotive or marine practice. To this end illustrations will be given of the most 
recent arrangements of Horizontal, Vertical, Beam, Pumping, Winding, Portable, Semi- 
portable, Corliss, Allen, Compound, and other similar Engines, by the most eminent Firms in 
Great Britain and America. ^ The laws relating to the action and precautions to be observed 
in the construction of the various details, such as Cylinders, Pistons, Piston-rods, Connecting- 
rods, Cross-heads, Motion-blocks, Eccentrics, Simple, Expansion, Balanced, and Equilibrium 
Slide-valves, and Valve-gearing will be minutely dealt with. In this connection will be found 
articles upon the Velocity of Reciprocating Parts and the Mode of Applying the Indicator, 
Heat and Expansion of Steam Governors, and the like. It is the writer's desire to draw 
illustrations from every possible source, and give only those rules that present practice deems 
correct. 



14 ' CATALOGUE OF SCIENTIFIC BOOKS 



Barlow's Tables of Squares, Cubes, Square Roots, 

Cube Roots, Reciprocals of all Liteger Numbers up to 10,000. Post 8vo, 
cloth, 6j-. 

Camus (M.) Treatise 07i the Teeth of Wheels, demon- 
strating the best forms which can be given to them for the purposes of 
Machinery, such as Mill-work and Clock-work, and the art of finding 
their numbers, translated from the French. Third edition, carefully revised 
and enlarged, with details of the present practice of Millwrights, Engine 
Makers, and other Machinists. By Isaac Hawkins. Illustrated by 
\Z plates, 8vo, cloth, 5^'. 



A Practical Treatise on the Science of Land and 

Engineering , Surveying, Levelling, Estimating Quantities, etc., with a 
general description of the several Instruments required for Surveying, 
Levelling, Plotting, etc. By H. S. Merrett. 41 fine plates with Illus- 
trations and Tables, royal 8vo, cloth, third edition, \2s. 6d. 

Principal Contents : 

Part I. Introduction and the Principles of Geometry. Part 2. Land Surveying ; com- 
prising General Observations — The Chain — Offsets Surveying by the Chain only — Surveying 
Hilly Ground — To Survey an Estate or Parish by the Chain only — Surveying with the 
Theodolite — Mining and Town Surveying — Railroad Surveying — Mapping — Division and 
Laying out of Land — Observations on Enclosures — Plane Trigonometry. Part 3. Levelling — 
Simple and Compound Levelling — The Level Book — Parliamentary Plan and Section — 
Levelling with a Theodolite — Gradients — ^Wooden Curves — To Lay out a Railway Curve — 
Setting out Widths. Part 4. Calculating Quantities generally for Estimates — Cuttings and 
Embankments — Tunnels — Brickwork — Ironwork — Timber Measuring. Part 5. Description 
and Use of Instruments in Surveying and Plotting — The Improved Dumpy Level — Troughton's 
Level — The Prismatic Compass — Proportional Compass — Box Sextant — Vernier — Panta- 
graph — Merrett's Improved Quadrant — Improved Computation Scale — The Diagonal Scale — 
Straight Edge and Sector. Part 6. Logarithms of Numbers — Logarithmic Sines and 
Co-Sines, Tangents and Co-Tangents — Natural Sines and Co- Sines — Tables for Earthwork, 
for Setting out Curves, and for various Calculations, etc., etc., etc. 



Saws : the History, Development, Action, Classifica- 
tion^ and Comparison of Saws of all kinds. By ROBERT Grimshaw. 
With 220 illustratiojis, 4to cloth, 12s. 6d. 

A Guide for the Electric Testing of Telegraph Cables, 

By Capt. V. Hoskiger, Royal Danish Engineers. With illustrations. 
Second edition, crown 8vo, cloth, a^s, 6d, 

Laying and Repairing Electric Telegraph Cables, By 

Capt. V. Hoskicer, Royal Danish Engineers. Crown 8vo, cloth, 
3J. bd. 



PUBLISHED BY E. & F. N. SPON. 15 



A Pocket-Book of Practical Rides for the Proportions 

of Moderji Engines and Boilers for Land and Marine purposes, Ijy N. P. 
Burgh. Seventh edition, royal 32mo, roan, 4^-. 6^. 

Details of High-Pressure Engine, Beam Engine, Condensing, Marine Screw Engines, 
Oscillating Engines, Valves, etc. Land and Marine Boilers, Proportions of Engines produced 
by the Rules, Proportions of Boilers, etc. 

Table of Logarithms of the Natural Ntmibers, from 

I to 108,000. By Charles Babbage, Esq., M.A. Stereotyped edition, 
royal 8vo, cloth, ^s. 6d. 

To ensure the correctness of these Tables of Logarithms, they were compared with Callett's 
Vega's, Mutton's, Briggs', Gardiner's, and Taylor's Tables of Logarithms, and carefully read 
by mne different readers ; and further, to remove any possibility of an error remaining the 
stereotyped sheets were hung up in the Hall at Cambridge University, and a reward offered 
to anyone who could find an inaccuracy. So correct are these Tables, that since their first 
issue in 1827 no error has been discovered. 

The Steam Engine considered as a Heat Engine : a 

Treatise on the Theory of the Steam Engine, illustrated by Diagrams, 
Tables, and Examples from Practice. By Jas. H. Cotterill, IvI.A.,' 
Professor of Applied Mechanics in the Royal Naval College. Svo cloth' 
I2s. 6d. & > , 

The Practice of Hand Titrning in Wood, Ivo7y, Shell, 

etc., with Instructions for Turning such Work in Metal as may be required 
in the Practice of Turning in Wood, Ivory, etc., also an Appendix on 
Ornamental Turning. (A book for beginners). By Francis Campln. 
Second edition, ijuith wood ejigravings, crown Svo, cloth, 6j. 

Contents : 

On Lathes— Turning Tools— Turning Wood— Drilling— Screw Cutting— Miscellaneous 
Apparatus and Processe.-Turning Particular Forms-Staining-Polishing-Spinning Metals 
— Materials — Ornamental lurning, etc. = *- & 

Health and Co7nfort in House Bnilding, or Ventila- 

Hon with Warm Air by Self-Acting Suction Fo-cuer, with Review of the 
mode of Calculatmg the Draught in Hot-Air Flues, and with some actual 
Experiments. By J. Drysdale, M.D., and J. W. Hayward M D 
Second edition, with Supplement, demy Svo, with plates, cloth, js. 6d. 

Treatise on Watchwork, Past and Present. By the 

Rev. H. L Nelthropp, M.A., F.S.A. Numerous illustrations, ciov^n 
Svo, doth, 6.. 6d. Contents : 

Definitions of Words and Terms used in Watchwork-Tools-Time-Historical Sum- 
mary-On Calculations of the Numbers for Wheels and Pinions; their Proportiona Siz^s 
I["5^L^V'e;^^^^H"^ H ^"'^V'f ^|otion Work-Length of Time of Going w^hout Winding 
W^i k'^ r te Horizontal- 1 he Duplex-'Ihe Lever-The Chronomeler-Repeatin| 
?^vor Ht7. Tf'l '"'"n^Ti^-^^"?^!^""^' ""' Spiral Spring-Compensation-Jewelling o^* 
Ti^^ U?e i WaSh e'r^ ^ ^'^" °^ '^' Trade-Incapacity of Workmen-HoW to Ch^e 



1 6 PUBLISHED BY E. & F. N. SPON. 

Now in Course of Publication. 

To be completed in about 30 Monthly Parts, each Part containing 64 pp., 
with mimeroiis illustrations, super-royal 8vo, price 2s. ; or in 5 Divisions, 
cloth, price I3J-. 6^. each. 

DIVISIONS I., n., & ni., now eeady. 

■SPOxNS' ENCYCLOPEDIA 



OF THE 



INDUSTRIAL ARTS, MANUFACTURES, AND COMMERCIAL 

PRODUCTS. 

Now in Course of Publication. 

To be completed in about 18 Monthly Parts, each Part containing 64 pp., 
with mcmerous illustrations, super-royal Svo, price 2s, ; or in 3 Divisions, 
cloth, price 13J'. 6^. each. 

DIVISIONS I. AND H. NOW EEADT, 

A SUPPLEMENT 

TO 

SPONS' DICTIONARY OF ENGINEERING, 

Edited by ERNEST SPON, Memb. Soc. Engineers. 



London: E. & F. N. SPON, 16, Charing Cross. 

New York : 446, Broome Street. 



